Install internal headers for Go bindings

Go, and likely other language bindings will, need access to create
new combinators. This functionality is currently located
src/parsers/parser_internal.h. Install this header to the system with
dependent headers until a better solution can be found.
Properly name the lib

Set the proper path for the shared library so that anything linking
against it will be able to find the library.
Fix for linux

This actually is only for OS X. On linux ldconfig must be run after
installing in order to update the library cache. Need to look into how
to get scons to do this for the user.
Merge branch 'master' of github.com:UpstandingHackers/hammer
Add warning message

Specify warning for internal only headers that are now installed for use
by extensions.
Merge pull request #58 from jrozner/master

Changes for doing a proper system install and Go bindings