Add callback option.
Fix comment.
use temporary fix for svgicons2svgfont that implements rounding
use different source for svgicons2svgfont
pass in ascent to svgicons2svgfont
add horizontal translation option
expose and pass in customWidth option to svg generator
use custom svg2ttf source in package.json
use autoHint options object

--windows-compatibility was causing some icons to disappear, so
allow that option to be set manually
only clean generated font files when building, not all fonts
pass in usWinAscent option to svg2ttf