* Since the MIT license is LGPL-compatible, there is no real point in
shipping FTGL under a dual license. Consequently removing LGPL references
from the code, in agreement with Sean.
* Moved header files that are not required by library clients into src/
so that they do not get installed.
* Created an ftgl.h header that allows clients to #include <FTGL/ftgl.h> and
be done with it.
