cache souper queries in a Redis DB
Add lit-based integration test infrastructure

Also add a few integration tests for the solver interface and the pass.
Merge pull request #28 from regehr/master

cache souper queries in a Redis DB
Remove a few unnecessary includes
Move InstMapping and PrintReplacement to Inst library
Add Parser library

This is for parsing instructions in souper inst format. The intention is
that the output of the souper command can be piped directly into this.
Add souperweb tool

This is a web based tool that can be used to harvest simplifications from
LLVM IR, or to check user-supplied simplifications in inst format.
Merge remote-tracking branch 'upstream/master' into overflow-instructions
Fixed bswap and sadd/uadd instructions as per review comments by John

bswap - no need to do AND for shifting bits by 24 for i32 integers and
no AND reqd. when shifting by 56 bits in i64 integers.
saddo and uaddo - no need of undefined behavior helper functions here,
as by adding an undefined behavior, we say do anything in case of
overflow but here we are inetersted in making overflow defined.

TODO : extractvalue instruction