added graph slice code + test
Merge branch 'master' into slice
added slice to resources
aaaand one more py3 unicode fix, really fixes #270 :)
added plugin infrastructure for sparql-update plugins and a graph.update method
added a bit of URI validation - fixes #266
merged https://github.com/dgerber/rdflib.git - fixes #258
Merge branch 'master' into slice
simplified slice syntax for graph/resources. Fixes https://code.google.com/p/rdflib/issues/detail?id=202 :)
Merge pull request #271 from RDFLib/slice

Slices as syntactic sugar for graphs / resources
examples updates, some slice fixes
moved paths from sparql package to top-level - make slicing return tuples, not always triples
keep order of projected variables and expressions - fixes https://github.com/RDFLib/rdflib-sparql/issues/9
fix doctests for py3
removed namespacedict, no usage found online or anywhere else
made Namespace no longer subclass uriref
make sure literal lang-tags are valid, re #266
New URIPattern utility class. Updates #258
changelog update
removed namespace.__str__ again