Indic language support.

Add missing polyglossia `gloss-*.ldf` files so that appropriate fonts
are selected for Assamese, Gujarati, Marathi, Oriya, and Punjabi.

(Note that the Marathi gloss corrects a typo in the upstream gloss.)

Change-Id: Iba4b904a738c59cc585a3cd29543d420d8b8c192