Convert build chain to fontmake

[m4rc1e]

Currently the chain consists of Robofab and some super old dependencies. If this project continues, it may be wise to invest the time and move it to fontmake

In the process this should solve #234 and #55.

[jamesgk]

I started a "fontmake" branch for this, but hit a wall trying to port the italicizing code to Defcon. More recently, more comprehensive masters have been under development so that automatic italicizing (which was always a bit of a dark art) and other weird steps can be removed from the build process entirely, then we can basically just store masters here and use fontmake.

[davelab6]

I propose to "backport" the release TTFs into 'source' UFOs that fontmake can compile; and make them interpolatable such that a variable font is possible; no port of italicizing code required.

[madig]

Any news on fontmake efforts or these new masters?

[davelab6]

See github.com/typenetwork/roboto

[davelab6]

Closing since this was done there