Merge pull request #2 from jackjennings/master

Make extensions installable/updatable with Mechanic
show mouse coordinates

replaces showdelta
typo!
readme update
replaced script with .roboFontExt
readme
readout position changes with glyph window resize
subclass a pen from a fontTools BasePen
Merge pull request #3 from typemytype/master

subclass from fontTools BasePen for creating pen objects
configure Show Mouse Coordinates for Mechanic