GUI:
	+ overlapping objects (e.g. 2 fat lines crossing on silk) are darker on the overlap; we need uniform color
	+ mouse scroll wheel doesn't work in cross section
	- zoom hangs: press {z z} on the drawing area -> hang
	+ xor draw fails after {w l} library footprint placement; in fail mode there's no xor outline of buffer; drawing a line fixes it
	- layer selector vertical layer group name truncation
	- main window resize scroll bar warnings
	- component draw "flicker", depending on pan: http://igor2.repo.hu/tmp/gtk3_bug1a.jpg http://igor2.repo.hu/tmp/gtk3_bug1a.jpg
	- missing grid points: http://igor2.repo.hu/tmp/gtk3_bug2.png

low prio/optional:
	- elliptic arc rendering

scconfig:
	- ./configure --buildin-hid_gtk3_cairo ends up depending on hid_gl; have to use --disable-lib_hid_gl
	- detect gtk3 calls the code depends on
