Add changelog entry for BBB freeswitch build
Change some settings in gbp for better downstream usage.
Disable some modules that we don't need to speed up build.

Also, enable mod_shout
Use the default builder command, it has better exclude/filter options
Move some 'gbp' options to the DEFAULT section

This means that various other commands share the tag names, etc.
Disable lintian; it fails checks and they won't be fixed.