Start of Aggregate parsing.
Progress on GROUP BY.
Implemented extend operation along with strdt and strlang.
Added numeric functions abs, ceil, floor, is_numeric, rand and round.
Add string functions: concat, contains, encode_for_url, lcase, replace, strafter, strbefore, strends, strlen, strstarts, substr, and ucase.
Added md5, sha1, sha256, sha384, and sha512 functions.
Add Date functions, note that RDF::Litearl::DateTime cannot distinguish between a time with a timezone of GMT vs no timezone.
Update to use #tz and #timezone methods for Literal::DateTime
Added BNODE and IRI/URI functions.
As per note in COALESCE, In SPARQL, evaluating an unbound variable raises an error. This causes minor changes to #bound and #order.
Added if, coalesce, uuid and struuid functions.
Enable bind tests.
Create SSE construct_spec with bound/unbound query tests.
Separate ask and describe specs out from query_spec.
This addresses issue #8, but requies un-released changes to the rdf gem.
Fix Gemfile.
Merge changes from master, fix some algebra representation issues.
Rename conflicting shared example names.
Reasign $stderr during tests.
Use rdf-aggregate-repo from GitHub.
Support for in and notin operators.
Fix problems with ask results, which may be either true or false, and need to be tested as RDF Literal values, not native boolean.