Add chat layout; change layout upon renaming

The chat layout is added after the NULL-layout line, thus requiring a
little adaption of the code that handles the layout list.

Whenever a workspace is renamed to (or attempted to rename to) 'chat',
the chat layout is applied.

Update Makefile (according to http://github.com/ayekat/Makefile).
Fix Makefile; fix die() bug

If one writes

	if (dada)
		die("blabla");

*without* the surrounding braces... well, classic beginner error.