* First round of adding fea output
No format tests but all test files give reasonable output so far.
* Get existing tests working
* Initial tests that work for fea2fea
* Get more tests working
Bug fixes and re-layout some tests to compare with fea2fea output.
Ranges and name parameters are not optimised yet.
* Handle vertical default values in fea2fea
* Hide fea2fea differences in lookupflags
* No reduce() in py3 so use a for loop
Before this change, feaLib did not handle feature files that specified
`feature aalt` whose block just was referring to other features without
defining any lookups on its own. After this change, we can handle it.
Resolves https://github.com/behdad/fonttools/issues/441
