5a017f58c4
The AM_CONDITIONAL always need to be evaluated, regardless of whether we are building with or without gl plugins (the actual checks are only called in AG_GST_GL_PLUGIN_CHECKS).
All aclocal .m4 files we need are put here and cat'd to acinclude.m4 in the source root. Official ones (taken from the relevant devel packages) are named as-is, unofficial ones (or changed ones) get a gst-prefix.