Make cps-selectors command take a real typeface
Make naming of selectors argument more consistent
added and changed comments
updated submodule ufoJS
use the precision argument according to the new ufoJS API

this was discussed in: https://github.com/graphicore/ufoJS/pull/8
make precision argument of commands/export.js an option
added missing parameter
Merge pull request #138 from rrthomas/cps-selectors

Cps selectors
Non-functional skeleton of an interpolate command
Take into account comments from @graphicore

Don't use for...in for array iteration

Don't store return value of project.open, as it's the same each time for the
same project.

Don't expect the code to work yet as a result of these changes!