split Indonesian (Arab Melayu) and Indonesian (Arab Pegon)

Originally this is a "bug fix". There were changes in the Indonesian layouts: "Arab Melayu" was renamed to "Arab Pegon". But Arab Melayu and Arab Pegon are slightly different, so that renaming Arab Melayu to Arab Pegon is a bug. The fix I propose is to split them.

1. Revert Arab Pegon to Arab Melayu.
2. Change phonetic to melayu-phonetic and phoneticx to melayu-phoneticx.
3. Introduce a new layout pegon-phonetic.

I write Arab Melayu, but not too familiar with Arab Pegon, so that I take Arab Pegon letters from Wikipedia.

This is the key differences between melayu-phonetic and pegon-phonetic:

Latin	Arab Melayu	Arab Pegon
dh	N/A	ڎ
th	N/A	ڟ
k	ک‎	ك
g	ݢ	ڮ
ny	ڽ	ۑ
v	ۏ *	ۏ

* Not common to all Arab Melayu sub-variants (some uses this, some doesn't use)