Copy code from fea_ParseGDEFTable().
Since this code was already in this same file, no changes to copyright
or licensing are necessary.  Since this code was written by George Williams,
nobody else can claim copyright on it.
Adjust George's code to work in its new location, fix formatting, give
variable a more informative name.
Merge branch 'master' into ligature_caret
resolve merge conflict
Conflicts:
	fontforge/featurefile.c
Merge pull request #578 from mskala/ligature_caret

Ligature caret in FEA syntax changes