[RaghuMalayalam] Dotreph glyph cleanup
[RaghuMalayalam] Change the glyph of Malayalam zero
[RaghuMalayalam] Remove experimental Samvruthokaram sign
[RaghuMalayalam] Correct GSUB rules for സ്റ്റ ഴ്ത്ത യ്ക്ക ക്ഷ്മ
[RaghuMalayalam] Use glyph references for zwj based chillus