finish openbsc / libosmocore separation

* use pkg-config from openbsc to find header and library
* move sms and timer tests to libosmocore itself
* ensure "make distcheck" works on both packages
diff --git a/libosmocore/include/osmocore/Makefile.am b/libosmocore/include/osmocore/Makefile.am
index aec27d1..189c767 100644
--- a/libosmocore/include/osmocore/Makefile.am
+++ b/libosmocore/include/osmocore/Makefile.am
@@ -1,2 +1,4 @@
-pkginclude_HEADERS = signal.h linuxlist.h timer.h talloc.h msgb.h select.h \
-		     tlv.h bitvec.h comp128.h statistics.h gsm_utils.h
+osmocore_HEADERS = signal.h linuxlist.h timer.h talloc.h msgb.h select.h \
+		   tlv.h bitvec.h comp128.h statistics.h gsm_utils.h utils.h
+
+osmocoredir = $(includedir)/osmocore