Add a lot more tests
Unhardcode enums, in preparation for version-conditional enumerators
Support LLVM 3.0
Support LLVM 2.9 at the raw level only

Supporting it at the high level would be complicated.
Add a testcase for recursive struct types

The horrible way LLVM 2.9 did this made me realize the point
of the StructSetBody API.
Support LLVM 3.2
Support LLVM 3.3
Handle multiple versions better
Add travis config