Arabic/Right to Left support

[sigmagamma]

I ported the P2 Arabic mod to P2CE as a local addon.

• Arabic captions are looking good, except for the final punctuation marks, which seem to move to the beginning of the last sentence (see the attached image).
• A caption in Arabic in the subtitles_english.kv3 file results in an "Unable to determine buffer encoding." message unless all of those captions have a bold tag in the beginning.

A huge thanks to everyone involved in supporting RTL languages.

Update:
The punctuation mark issue can be worked around by adding a right to left mark ( '\u200f' ) following the punctuation marks at the end