Add header files to libraries

This ensures that the headers show up in an IDE
like Xcode when that IDE is used as the cmake
target.

This is not necessary for building and dependency
tracking.
Merge pull request #7 from jeroenk/header

Add header files to libraries
Stop giving the name "arr" to unnamed variables; instead do that in the KLEE builder
Make a start on caching solver
Roll LLVM to r209252
Remove references to OwningPtr
Add virtual destructor to Solver class
Factor out files included in libraries
Factor out the core of ExtractExprCandidatePass
Add Souper llvm opt pass
Document pass
Fix use-without-inclusion error
Changes per Peter's feedback
Merge pull request #11 from jeroenk/pass-new

Add souper llvm compiler pass - take 2
Silence Mac ld warning regarding weak symbols
Merge pull request #12 from jeroenk/mac-ld

Silence Mac ld warning regarding weak symbols