[FINAL] optimal size clean up revert

During https://github.com/mindsnacks/moai-dev/pull/47, an attempt was made to clean up a small amount of duplicated code. It turns out that the second occurrence of the code wasn't actually redundant so this reverts the change made in PR 47. (Details: the variable `lineHeight` was assumed to never change within the do while loop so was moved out...turns out the `FT_Set_Char_Size` made non-obvious changes to `face` per iteration)