Basic IR tuples; have not included CALL/RET tuples for now
Added basic IR block class; may need to come up with a name better than 'backend' for directory later
Removed ALLOC; made changes to tuple and block structures to make it easier to form graphs
Added IRGraph class; so far, only splitting up streams of IR into basic blocks (no successors indicated)
Declaration stuff added
Graph building now adds successors
Merge branch 'master' of https://github.com/tcd-swift/tcd-swift into shayan
Added more declaration and type grammar
Revert "Copied Shayan's declaration stuff"

This reverts commit 48281b50dcf11326b68a858adf9056404859554e.
Merge remote-tracking branch 'origin/shayan' into grammar