Move src/*.{c,h} to src/core/

This way we have all libosmocore.so in an own subdir instead of having
lots of files in the parent dir, which also contains subdirs to other
libraries.
This also matches the schema under include/osmocom/.

Change-Id: I6c76fafebdd5e961aed88bbecd2c16bc69d580e2
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 8c7e40a..f0eaaca 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,7 +1,7 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
 AM_CFLAGS = -Wall $(TALLOC_CFLAGS) $(PTHREAD_CFLAGS)
 AM_LDFLAGS = -no-install
-LDADD = $(top_builddir)/src/libosmocore.la $(TALLOC_LIBS) $(PTHREAD_LIBS)
+LDADD = $(top_builddir)/src/core/libosmocore.la $(TALLOC_LIBS) $(PTHREAD_LIBS)
 
 if ENABLE_SERCOM_STUB
 noinst_LIBRARIES = libsercomstub.a
@@ -93,7 +93,7 @@
 
 stats_stats_test_SOURCES = stats/stats_test.c
 stats_stats_test_LDADD = $(LDADD) $(top_builddir)/src/gsm/libosmogsm.la
-stats_stats_test_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/src
+stats_stats_test_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/src/core
 
 stats_stats_vty_test_SOURCES = stats/stats_vty_test.c
 stats_stats_vty_test_LDADD = $(LDADD) $(top_builddir)/src/vty/libosmovty.la
@@ -209,7 +209,7 @@
 gb_gprs_ns2_test_LDADD = $(LDADD) $(LIBRARY_DLSYM) \
 			$(top_builddir)/src/vty/libosmovty.la \
 			$(top_builddir)/src/gsm/libosmogsm.la \
-			$(top_builddir)/src/libosmocore.la \
+			$(top_builddir)/src/core/libosmocore.la \
 			$(top_builddir)/src/gb/libosmogb-test.la
 if ENABLE_LIBMNL
 gb_gprs_ns2_test_LDADD += $(LIBMNL_LIBS)