By default systemd will execute service with root directory
(or home directory for user instance) which might result in
attempts to create files in unexpected place. Let's set it
to 'osmocom' subdir of state directory
(/var/lib for system instance) instead.
Related: OS#4821
Change-Id: I4b7bcd441e5da81c4c5267715675041171a1ce1e
Change cfg file names so they don't overlap when installing different
osmo-bts versions, and make systemd services look for correct new name.
Remove unneeded duplicated EXTRA_DIST files from root dir Makefile.am
Change-Id: I75fdd06cc52ce50628efb1f9b007d2e3926db27d