Support static modules aka modules which are embedded inside libts

Support static modules aka modules which are embedded inside libts

This can be usefull for statically linked application or platforms
where dlopen(3) is not available.

A module will be compiled statically if it was requested during
./configure with --enable-$FOO=static.

Static modules will have precedence over shared ones which means
if a module is configured to be embedded inside libts it's
corresponding shared library isn't build and ignored even if
it is in $TSLIB_PLUGINDIR.

Signed-off-by: Marc Andre Tanner <mat@brain-dump.org>
Signed-off-by: Chris Larson <clarson@mvista.com>