* make KDE support work again

	After cleaning up the autotools config, twinkle only builds with
	--without-kde. This is only temporary, the goal is to allow building
	against KDE4 libraries (and, preferrably, also KDE5).

* IPv6 support

	Still missing, AFAIK.

* t_gui locking

	Dirty workaround for (mostly) calling GUI related methods from non-GUI
	threads. Doesn't actually work with Qt4, causing segfaults. Analyze
	the remaining uses and get rid of it.

* MEMMAN_* tracking macros

	Ugly and unreliable (too easy to forget adding them). Either replace
	them with overloaded new and delete operators or kill them completely
	and rely on valgrind.