SMC Malayalam fonts release 6.0

* Combined mlym, mlm2 Opentype script specification support in Meera, Rachana
  and RaghuMalayalamSans
* Full support to Harfbuzz and Uniscribe shaping engines
* Cleaned up and updated lookup tables
* Meaningful names to glyphs to help with Lookup tables reusability
* Old Figures and other Typographical glyphs such as double quotes to Rachana
* Dotreph positioning using GPOS 'abvm' lookup
* Unicode 6.1 Malayalam glyphset for many fonts
* Improved Latin glyphs and kerning for Meera
* Experimental usage of reference glyphs for some conjunct glyphs
* Removed hinting instructions, reduced TTF file size
* Several bugfixes, lookup corrections, glyph improvements
* Many test cases added