cmake: Install lib and headers
cmake: Install lib and headers

Note files are installed into gl4es namespace to avoid overlap,
with system's opengl files.

This is useful for distro packagers

Signed-off-by: Philippe Coval <66e956a7574c7a5229d4addfdb6368e0afbbfd45@users.sf.net>
Change-Id: I3f2648b3c5da03693cf2a6bf47ae089bd207cee2

ptitSeb/gl4es,ptitSeb/gl4es,ptitSeb/glshim,ptitSeb/glshim,ptitSeb/glshim,ptitSeb/gl4es,ptitSeb/glshim,ptitSeb/gl4es