Removal of XML parsers: pyRXP, 4suite

* Removes pyRXP from the mandatory dependencies (#1797)
* Removes 4suite (their website says to not use it anymore :haircut:)
* Some PEP8/257 :heart: 
* **NOTE** if pyRXP is installed, it will still be used instead of lxml. If anything breaks, write more tests.
4: I102 copyright year is outdated, expected 2014 but got 2013
32:1: F401 'etree' imported but unused
35:5: F401 'pyRXP' imported but unused
47:17: E128 continuation line under-indented for visual indent
74:16: E713 test for membership should be 'not in'
115:1: E302 expected 2 blank lines, found 1
237:13: E225 missing whitespace around operator
240:34: E225 missing whitespace around operator
265:34: E225 missing whitespace around operator
289:34: E225 missing whitespace around operator
313:35: E225 missing whitespace around operator
317:1: E302 expected 2 blank lines, found 1
352:1: E302 expected 2 blank lines, found 1
393:25: E128 continuation line under-indented for visual indent
393:492: E231 missing whitespace after ','
426:29: E231 missing whitespace after ','
500:25: E128 continuation line under-indented for visual indent
610:1: E302 expected 2 blank lines, found 1
641:53: E128 continuation line under-indented for visual indent
643:53: E128 continuation line under-indented for visual indent
654:53: E128 continuation line under-indented for visual indent
656:53: E128 continuation line under-indented for visual indent
656:63: E251 unexpected spaces around keyword / parameter equals
667:53: E128 continuation line under-indented for visual indent
668:53: E128 continuation line under-indented for visual indent
670:53: E128 continuation line under-indented for visual indent
671:53: E128 continuation line under-indented for visual indent
678:13: E128 continuation line under-indented for visual indent
680:13: E128 continuation line under-indented for visual indent
687:14: E128 continuation line under-indented for visual indent
689:14: E128 continuation line under-indented for visual indent
690:14: E126 continuation line over-indented for hanging indent
694:1: E302 expected 2 blank lines, found 1
722:13: E128 continuation line under-indented for visual indent
724:13: E128 continuation line under-indented for visual indent
729:13: E128 continuation line under-indented for visual indent
733:13: E128 continuation line under-indented for visual indent
735:13: E128 continuation line under-indented for visual indent
740:13: E128 continuation line under-indented for visual indent
742:13: E128 continuation line under-indented for visual indent
745:13: E128 continuation line under-indented for visual indent
747:13: E128 continuation line under-indented for visual indent
749:13: E128 continuation line under-indented for visual indent
755:13: E128 continuation line under-indented for visual indent
757:13: E128 continuation line under-indented for visual indent
759:13: E128 continuation line under-indented for visual indent
761:13: E128 continuation line under-indented for visual indent
763:1: E302 expected 2 blank lines, found 1
828:53: E128 continuation line under-indented for visual indent
836:53: E128 continuation line under-indented for visual indent
914:13: E128 continuation line under-indented for visual indent
918:13: E128 continuation line under-indented for visual indent
920:13: E128 continuation line under-indented for visual indent
922:13: E128 continuation line under-indented for visual indent
924:13: E128 continuation line under-indented for visual indent
929:13: E128 continuation line under-indented for visual indent
930:13: E128 continuation line under-indented for visual indent
932:13: E128 continuation line under-indented for visual indent
933:13: E128 continuation line under-indented for visual indent
960:13: E128 continuation line under-indented for visual indent
962:13: E128 continuation line under-indented for visual indent
968:13: E128 continuation line under-indented for visual indent
969:13: E128 continuation line under-indented for visual indent
971:13: E128 continuation line under-indented for visual indent
972:13: E128 continuation line under-indented for visual indent
974:13: E128 continuation line under-indented for visual indent
975:13: E128 continuation line under-indented for visual indent
1009:13: E128 continuation line under-indented for visual indent
1011:13: E128 continuation line under-indented for visual indent
1016:13: E128 continuation line under-indented for visual indent
1017:13: E128 continuation line under-indented for visual indent
1019:13: E128 continuation line under-indented for visual indent
1020:13: E128 continuation line under-indented for visual indent
1022:13: E128 continuation line under-indented for visual indent
1023:13: E128 continuation line under-indented for visual indent
1025:1: E302 expected 2 blank lines, found 1
1054:13: E128 continuation line under-indented for visual indent
1058:13: E128 continuation line under-indented for visual indent
1062:13: E128 continuation line under-indented for visual indent
1067:13: E128 continuation line under-indented for visual indent
1068:13: E128 continuation line under-indented for visual indent
1070:13: E128 continuation line under-indented for visual indent
1071:13: E128 continuation line under-indented for visual indent
1073:13: E128 continuation line under-indented for visual indent
1074:13: E128 continuation line under-indented for visual indent
1115:58: E261 at least two spaces before inline comment
1191:13: E128 continuation line under-indented for visual indent
1193:13: E128 continuation line under-indented for visual indent
1195:13: E128 continuation line under-indented for visual indent
1200:13: E128 continuation line under-indented for visual indent
1201:13: E128 continuation line under-indented for visual indent
1203:13: E128 continuation line under-indented for visual indent
1204:13: E128 continuation line under-indented for visual indent
1206:13: E128 continuation line under-indented for visual indent
1207:13: E128 continuation line under-indented for visual indent
1247:13: E128 continuation line under-indented for visual indent
1249:13: E128 continuation line under-indented for visual indent
1251:13: E128 continuation line under-indented for visual indent
1253:13: E128 continuation line under-indented for visual indent
1255:13: E128 continuation line under-indented for visual indent
1259:13: E128 continuation line under-indented for visual indent
1261:13: E128 continuation line under-indented for visual indent
1263:13: E128 continuation line under-indented for visual indent
1264:13: E128 continuation line under-indented for visual indent
1268:13: E128 continuation line under-indented for visual indent
1270:13: E128 continuation line under-indented for visual indent
1271:17: E128 continuation line under-indented for visual indent
1475:1: E302 expected 2 blank lines, found 1
1482:13: E128 continuation line under-indented for visual indent
1488:13: E128 continuation line under-indented for visual indent
1490:13: E128 continuation line under-indented for visual indent
1492:13: E128 continuation line under-indented for visual indent
1494:13: E128 continuation line under-indented for visual indent
1497:13: E128 continuation line under-indented for visual indent
1499:13: E128 continuation line under-indented for visual indent
1502:13: E128 continuation line under-indented for visual indent
1505:13: E128 continuation line under-indented for visual indent
1513:13: E128 continuation line under-indented for visual indent
1515:13: E128 continuation line under-indented for visual indent
1521:13: E128 continuation line under-indented for visual indent
1523:13: E128 continuation line under-indented for visual indent
1529:13: E128 continuation line under-indented for visual indent
1531:13: E128 continuation line under-indented for visual indent
1533:1: E302 expected 2 blank lines, found 1
1561:13: E128 continuation line under-indented for visual indent
1562:13: E128 continuation line under-indented for visual indent
1564:13: E128 continuation line under-indented for visual indent
1565:13: E128 continuation line under-indented for visual indent
1567:13: E128 continuation line under-indented for visual indent
1568:13: E128 continuation line under-indented for visual indent
1573:13: E128 continuation line under-indented for visual indent
1574:13: E128 continuation line under-indented for visual indent
1576:13: E128 continuation line under-indented for visual indent
1577:13: E128 continuation line under-indented for visual indent
1579:13: E128 continuation line under-indented for visual indent
1580:13: E128 continuation line under-indented for visual indent
1582:1: E302 expected 2 blank lines, found 1
1622:1: E302 expected 2 blank lines, found 1
1637:78: E231 missing whitespace after ','