New methods to support getting the document vectors out of a VSM

	modified:   src/main/java/edu/ucla/sspace/common/GenericTermDocumentVectorSpace.java

- Added new optionally supported methods for returning the document vectors of an instance

	modified:   src/main/java/edu/ucla/sspace/lsa/LatentSemanticAnalysis.java

- Updated to override the documents methods of GenericTermDocumentVectorSpace

	modified:   src/main/java/edu/ucla/sspace/matrix/MatrixBuilder.java

- Fixed typo

	modified:   src/main/java/edu/ucla/sspace/vsm/VectorSpaceModel.java

- Added support for getting the document methods

	new file:   src/test/java/edu/ucla/sspace/vsm/VsmTest.java

- Added minimal unit tests to verify things work as expected
Merge branch 'master' of https://github.com/fozziethebeat/S-Space