[Meera] Introduce anchror class 'chandrakkala' and remove glyphs with chandrakkala

No need of explicit glyphs with chandrakkala. Kept y1xx, v1xx, l1xx
because of potential issues in old shapers

Reduces font size further:
Meera.ttf: 304KB
Meera.woff: 142KB
Meera.eot: 124KB

Target: get the webfont size below 100KB mark :)