Posting a SPARQL command does not require urlencode
Allows the client to choose which POST type use in SPARQLUpdateStore
Reverse the postAsEncoded parameter in order to back-compatibility
Cleaned some duplicated lines and spurious comments
Optimization for IOMemory's __all_triples. fixes #318

Adding a __contextTriples index allows us to efficiently look-up
all triples in one context at linear cost of the store's size.
This is a common operation for example during serialization.

The previous implementation got along without this index, but
serializing a dataset with a lot of graphs took quadratic time.
Added support for single-quoted Turtle string literals.
pyRdfa: superfluous warning was generated for an <a> element's @rel value, with a simple term and in RDFa Lite
Fixed duplicate creation of namespace prefixes
Only accept single quotes around strings when parsing Turtle, not N3.
Added test for #326 (accept single quotes around Turtle strings)
Correct indentation in python sample code
Make sample code working

Change:
- two bad indentations,
- one unwanted ],
- missing URIRef import.
Missing )
Correct error in sample codes

- invalid indentation,
- unwanted :.
Better to show subject instead of object

We are searching persons. It's better to display:
    http://example.org/people/Bob is a person
than
    http://xmlns.com/foaf/0.1/Person is a person
Method is subjects(), not subject()
Merge pull request #332 from PuckCh/patch-1

Correct indentation in python sample code
Bad indentation in sample code
Make sample code working

- one unwanted ],
- missing URIRef import.
Merge pull request #333 from PuckCh/patch-2

Make sample code working