Add code to parse a debug category string

Use strdup to be able to use strtok on the category string and add
a test case. Also safe some more information to be able to use color
in the print statement.
diff --git a/tests/debug/debug_test.c b/tests/debug/debug_test.c
new file mode 100644
index 0000000..4fe539c
--- /dev/null
+++ b/tests/debug/debug_test.c
@@ -0,0 +1,34 @@
+/* simple test for the debug interface */
+/*
+ * (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <openbsc/debug.h>
+
+
+int main(int argc, char** argv)
+{
+    parse_category_mask("DRLL");
+    DEBUGP(DCC, "You should not see this\n");
+
+    parse_category_mask("DRLL:DCC");
+    DEBUGP(DRLL, "You should see this\n");
+    DEBUGP(DCC, "You should see this\n");
+    DEBUGP(DMM, "You should not see this\n");
+}