Replace almost all instances of ICU with OT or OpenType as appropriate
tidy up main \fontspec_select:nn macro 

includes a few fontspec->@@ renames
a whole bunch of @@ replacing

finally
document how to ignore Scale=MatchLowercase for \setmainfont

from a discussion on github:
https://github.com/wspr/fontspec/issues/165

thanks!
just for now while l3docstrip is updated
add support for debug guards

not sure how much i'll want to garbage up the source
copyright dates
consider a weird new interface

(might totally change my mind on this)
brain dump (sorry) introducing NFSSShape

this commit, among other internal code changes, adds the 
NFSSFont feature to be able to write things like:

  NFSSFont = {nc}{n}{Helvetica},
  NFSSFont = {c}{n}{* Ultra Light}{Color = FF0000},

and also

  NFSSFont = {c}{n}{Times}{
    SizeFeatures = {
      {Size = -10,Color = FF0000,Font=Georgia},
      {Size = 10-15,Color = FF00FF},
      {Size = 15-,Color = 0000FF,Font=Cochin},
    },
  },

This may eventually lead into a more flexible interface.
deprecated
rethink test suite

(hopefully to be replaced by the latex3 test system at some point)
gitignore
recent bugs caught with tests