Streamlined quickcheck tests by removing duplication

All tests are now defined in Data.RDF.GraphTestUtils.hs . New graph
implementations only need to provide implementations of

empty'     :: RDF rdf => rdf
mkRdf'     :: RDF rdf => Triples -> Maybe BaseUrl -> PrefixMappings -> rdf
triplesOf' :: RDF rdf => rdf -> Triples

See Data.RDF.MGraph_Test.hs for an example. Add your graph
implementation to `defaultMain` in Test.hs .
Merged cordawyn/master
moved `resolveQName` and a few other functions to `Data.RDF.Types`
resolveQName returns a Maybe value instead of immediately failing when
unable to look-up the prefix
refactored t_qname
Uses isAbsoluteURI from network-uri package

The rdf4h isAbsoluteUri uses isAbsoluteURI from network-uri, and this
function is moved to Data.RDF.Types . Fixes robstewart57/rdf4h#18 .
adds ghc-prim build dependency for ghc < 7.6. Fixes robstewart57/rdf4h#13
Fixed regression introduced in edaaee283e3bbfd9af36dec3eaf67452472a0448

The correct function in Network.URI is `isURI`, which is documented
thus:

> "Test if string contains a valid URI (an absolute URI with optional
fragment identifier)."

RDF URIs are optionally appended with fragments e.g. `#foo`. The
edaaee283 commit incorrectly opted for `isAbsoluteURI`, which is not
the same as RDF URIs given the following haddock documentation:

> "Test if string contains a valid absolute URI (an absolute URI without
a fragment identifier)."

Also, this identified a new problem in the turtle parser tests from
`data/ttl/example7`, which includes "ns10:Édimbourg" in the parsing
test.

URIs conform to RFC3986 which does not support unicode, i.e. the É
symbol. IRIs conform to RFC3987 which includes unicode. The rdf4h
library does not include IRIs, only URIs, hence this unit test has
been disabled. See:

https://tools.ietf.org/html/rfc3986
https://tools.ietf.org/html/rfc3987
implemented `expandTriples`
exporting `expand*` functions
Merge branch 'robstewart57'

Conflicts:
	src/Text/RDF/RDF4H/TurtleParser.hs
added namespace expansion to other query functions
updated TODO
Merge pull request #19 from cordawyn/master

Triple, Node and URI expansion for TriplesGraph
Revert rdfContainsNode and listNodesWithPredicate

From 9dd4729908db8d2f80088706592adac81a0f3016
modified tests, as expansion is now deferred
version bump to 1.3.0
Initial patricia tree implementation
bring PatriciaTree implementation upto date with master
WIP Patricia Tree re-implementation