Add another heuristic to kerning computation
improve gray pixels
remove dead definitions in header
started work towards linear cores

Some fitting approaches expect to walk the glyphs linearly; only once,
preparing to add such a mode.
cli: implement commandline argument parsing

The parsed commandline is currently affecting the initial state of the gui
when launched, pressing reset to defaults will reset to factoy defaults; not
commandline defaults.
make commandline version support writing to different ufo folder (unix only for now)
make the main callback linear; and implement combinatorics inside
proper start of cadence
add cli.c
disambiguate statics
integrate cli with core kernagic
rename more files
remove some internal options from help
splitting combinatoric part out of core
continued modularization
invoke trigger_reload before main
remove unused bits of ui
added ink_prefix to some glyph members
further mini cleanups of ui
use a combo-box for the mode selector