shared-glapi: Install libglapi.so.0.0.0 and .0 links in lib/.

shared-glapi: Install libglapi.so.0.0.0 and .0 links in lib/.

We already provided these files on 'make install', but only created a
'libglapi.so' in the top-level lib/ convenience folder.  We used to
create all three, but at some point in the build system churn, it broke.

Various applications (like the ES2 conformance suite) seem to link
against libglapi.so.0, so without these links, setting LD_LIBRARY_PATH
and LIBGL_DRIVERS_PATH can lead to using /usr/lib/libglapi.so.0 with
/home/whatever/libGL.so, which leads to API calls getting routed
incorrectly (i.e. glCompileShader -> _mesa_LinkProgramARB), which leads
to rage problems.

Preserve developer sanity...install links.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>