Refactor

- pretty printers moved to pretty module
 - command and subcommands get own module

tools/gdb/python/main.py

@@ -0,0 +1,19 @@
+#
+# RTEMS GDB Extensions
+#
+# main
+
+import gdb
+import pretty
+import rtems
+
+gdb.pretty_printers = []
+gdb.pretty_printers.append(pretty.lookup_function)
+
+# Register commands
+# rtems and subcommands
+rtems.rtems()
+rtems.rtems_object()
+rtems.rtems_semaphore()
+rtems.rtems_task()
+rtems.rtems_message_queue()