Add some useful properties to contexts
We don't actually need ctypesgen to install
Add missing call to superclass constructor
Fix a few bugs in credentials
Export GSSAPI status codes
Add error checking before cast in Credential
Fix bad arguments for get/verify_mic and (un)wrap
Add generated header files from Linux (MIT)

These may have to go away at some point, or be generated at install time, or move to pre-generated x86/x64 versions.
Friendlier API

Make some parameter names more sensible.
Raise exceptions instead of returning tuples from Context.(un)wrap().
Make OIDSet take negative indexes, like lists.
More tests and bug fixes from testing.
Ignore some directories