The following sed command can be used to update TTX sources for the LookupType
change:
$ sed -i'~' 's/<!-- LookupType=\(.\) -->/<LookupType value="\1"\/>/g' *.ttx
I'll first make Python 2 and 3 both generate same output for tests with
MockFont, then will probably hardcode glyphorder and remove MockFont
completely and remove hacks I added to make tests work with MockFont.
