Fixed the cmake default which did not select the build type that it said.

The default is now really RelWithDebInfo.
As a byproduct, the backtrace is now leak-free (the leaky line number feature (in SLC5) is only present in Debug builds).
Relaxed the compilation for files with strict aliasing issues.
Gave a default value to a few variables which might e used uninitialized.
The unit tests hence pass again in SLC5.

mediachanger/castorrmc/rmc/rmc_logreq.c

@@ -19,7 +19,7 @@ void rmc_logreq(const char *const func, char *const logbuf) {
 	int n1, n2;
 	char *p;
 	char savechrs1[2];
-	char savechrs2[2];
+	char savechrs2[2] = { '\0', '\0' };
 
 	n1 = RMC_LOGBUFSZ - strlen (func) - 36;
 	n2 = strlen (logbuf);