Merge branch 'development_stuff' into 'master'

Development improvements

An improvement to Objectplace I've wanted to make for a loooong time.

* Object number up/down is now assigned to ringslinger weapon next/prev. SO much nicer to use, especially since most people have that stuff bound to the scroll wheel.

Also, some changes to the devmode overlay:

* Plays nicely with showfps on - see http://imgur.com/a/zSzvm for the various cases (showfps on, devmode 65535, and both).
* Add PF_THOKKED to the flags in devmode DBG_DETAILED (as "TH").
* "Flags:" replaced with "PF:", "Heap used" replaced with "Heap". The latter is a debatable change, but the former isn't - otherwise the line is way too long compared to the rest of the stuff.

See merge request !45