Added testing directories with several stubs.
Merge branch 'develop' into tfidf
Added tolist method to Corpus. Added corpus_fromlist function. Begin migration of vsm.util.corpustools to vsm.corpus.util.
added more tests.
Merge branch 'develop' into tfidf
Bug fix
Adding more tests.
Merge branch 'develop' into tfidf
All tests for corpus.
moved tests_corpus to unit_tests.