Support for Grantha

[ghost]

Unicode consortium has recently allocated a block to the Grantha script. It'd be nice to have a font for this included in Lohit. I think there are font faces which map to other blocks (e-Granthamil maps to Malayalam); I'm not sure what license these are under.

[pravins]

Will be nice if someone can work on this task. I would love to review and add it in upstream

[ghost]

I'll try giving it a shot. Is there some general guidelines I should look at (other than licensing ?).
Is it okay to use reserved slots in the Unicode block ?

The Grantha spec is missing characters like the हृस्व ऒ & ऎ, which I imagine are important for Tamil (but not so much for Sanskrit).