Assign special characters we still want after removing unwanted.
Assign special characters we still want after removing unwanted.

Unwanted characters ('EXCL') are by default excluded from all fonts,
but in a few cases we do want some.  This adds BOM to LGC and C0/C1
controls to Sym2.  It also corrects an omission of some PUA characters
that should be supported in color emoji for Android.

googlefonts/nototools,dougfelt/nototools,moyogo/nototools,googlefonts/nototools,moyogo/nototools,googlei18n/nototools,moyogo/nototools,anthrotype/nototools,googlefonts/nototools,googlefonts/nototools,anthrotype/nototools,dougfelt/nototools,googlei18n/nototools,googlei18n/nototools,anthrotype/nototools,googlefonts/nototools,dougfelt/nototools