Drop support for --enable-static.
gallium/auxiliary: Build libgallium shared.
Don't create symlinks on distribution builds.
mapi: Build libglapi always shared.
mesa: Build libmesa shared for distributions.

Mainly openSUSE and Ubuntu want more shared libs and not the mega...
You can control it via --enable-distro switch.
Install all internal shared libs to $(libdir)/mesa-$VERSION.
Also do it for egl_gallium.so, pipe_*.so and gbm_gallium_drm.
Makefile.am: s:-no-undefined:-Wl,--no-undefined to make it work.
gallium/drivers: Build libs -shared.
vdpau,xvmc: Add install-data-hooks to remove unneccessary symlinks.

libvdpau_*.so.1 and libXvMC*.so libs are dlopened by wrappers.
So only those libs should be installed.
glx: Get rid of libglx.la.
gbm: Get rid of libgbm_dri.la.
i915: Conditionally build an i915g driver instead of two i915 drivers.
gallium/auxiliary/draw/draw_decompose_tmp.h: Fix clang warnings.
More scan-build fixes.