implement strategy for query loader

[djogopatrao]

nowadays, only a list of classes is allowed as an input query; upon specification of -query_type sparql, it would accept an sparql query instead.

implementing strategy, we would easily expand this for other query formats.

[djogopatrao]

one possible query input format is dlquery

https://github.com/owlcs/owlapi/blob/master/contract/src/test/java/org/coode/owlapi/examples/DLQueryExample.java

[djogopatrao]

in the current commit ( 307f82b ), stuff like (live_example_property)
query: prop some E and A
domain:
B,C subclassof A
F subclassof E
D subclassof (prop some G)

renders a query specifiying service endpoint1 { prop some E union prop some F }, which may be correct. however, this expansion is being done at QueryExpander.createPatternFromRestriction, failing to check existence of subclasses of E in this endpoint (or others endpoints!).

this inference should be integrated at createPatternFromClasses. there is an underlying pattern between somevaluesfrom and rdf:type that can be used to simplify and generalize the whole algorithm.

I'm commiting as is, so the idea is not lost.