Revert "added the function split_letter()"
Revert "added the function split_letter()"

This reverts commit 2ecd95e5d05a4628fcd0a79a7962b50873563926.

tshrinivasan/open-tamil,tshrinivasan/open-tamil,tshrinivasan/open-tamil,tshrinivasan/open-tamil,tshrinivasan/open-tamil,tshrinivasan/open-tamil,tshrinivasan/open-tamil