#27 Added abstract StringNumber, created StringInteger and StringDouble from it, added StringDoubleList copying StringIntegerList format. Small change in import in InvertedLemmaIndexMapRed
#27 implemented JUnit tests. Cannot (easily at the moment) test readFields in all the String__ classes
Merged master into branch
Merge pull request #31 from gekonwi/steven.27.StringDouble

#27 Added abstract StringNumber, created StringInteger and StringDouble ...
#27: just renamed StringNumbersTest to StringNumberTest for consistency
#27: refactored StringNumber and affected classes.
Introducing a generic value type in StringNumber allows to make StringInteger and StringDouble even shorter.
#27: worked through the tests
#27: fixed all the failing TokenizerTest tests
(besides testRemovesCitationsPreservingDescriptionTitleAuthor -> issue #32)
Closes #27.
#23: merged in StringDouble etc.
#23: made sure lemmas with 100% probability for a certain profession are not ignored because of log(1.0) == 0.