White space fixes

Merge branch 'master' of github.com:johanmattssonm/birdfont

List all alternates

Merge branch 'master' of github.com:johanmattssonm/birdfont

Select replacement glyph in OTF feature tab
All alternate glyphs and the glyph that will replaced is referenced by name
(not unicode).

Generate swsh, salt, smcp and c2sc tables.
This commit adds support for swashes, stylistic alternatives, small caps and
conversion from uppercase to small caps

GUI for selecting OTF feature tags

Save stylistic alternatives to bf fonts and make gsub features optional

Generate stylistic alternates and fix PostScript names