fixes to go with rdflib literal fix branch
Improve ordering of Nodes

When ordering, unbound variables must come first, then blank nodes,
followed by IRIs and finally literals.[1]

This also fixes a Py3-incompatibility: NoneType is not comparable in
Py3.[2]

[1] http://www.w3.org/TR/2012/PR-sparql11-query-20121108/#modOrderBy
[2] file:///usr/share/doc/python3.2-doc/html/whatsnew/3.0.html#ordering-comparisons
Merge pull request #12 from uholzer/py3-None-comp

Ordering of Nodes and py3 compat
updated skip-tests;
fixed skipping update-tests
py3 fixes for csv result format
fix for different math.round behaviour in py3k
another fix for string-slash-decoding in py3k
... and added missing file
Refine travis envar use, extend to cover Py3.3
2.5/2.6 compat work
Merge branch 'master' of github.com:RDFLib/rdflib-sparql
added simplejson dep for 2.5
skipping more tests
tab/space confusion
merge master
many minor fixes to literal datatype handling
added xsd type-promotion
autopep8
Merge pull request #13 from RDFLib/rdflib-literalfix

Rdflib literalfix