Cleanup mrt_value_unref() a bit
Add some real testing starting with memory.[ch] module

Using CuTest since it's really easy to add into project and use.
Code dump
Rename MRT_Value to MRT_Object as top-level class
Rename MRT_/mrt_ prefix to M/M_/m_ to save typing

If GLIB can't take the whole g_* namespace I can take m_* :)
Another code dump