move log/debug codebase to libosmocore

The logging/debugging code is generic enough to move it into libosmocore
while keeping OpenBSC specific definitions in openbsc itself.

This commit uses the logging support present in libosmocore-0.1.2,
you will have to update your library to this version.
diff --git a/openbsc/configure.in b/openbsc/configure.in
index 27fb0ed..63d260a 100644
--- a/openbsc/configure.in
+++ b/openbsc/configure.in
@@ -18,7 +18,7 @@
 AC_SEARCH_LIBS(crypt, crypt,
     [LIBCRYPT="-lcrypt"; AC_DEFINE([VTY_CRYPT_PW], [], [Use crypt functionality of vty.])])
 
-PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 0.1.1)
+PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 0.1.2)
 
 dnl checks for header files
 AC_HEADER_STDC