indexing: gave up on merging the branches. added files manually
indexing: added programs and scripts for testing indexing on IMP
indexing: (1) added programs for testing indexing on Lambda
(2) fixed minor bugs in Unifier and AddInjections classes
indexing: removed unneeded files
indexing: got rid of bug in index retrieval
indexing: small cleanup
indexing: added TODOs
indexing: added files to test indexing on simple, started making it work