Add translation support

[shoghicp]

Since we have the PocketMine translation Center we can use it to provide translated strings on the app.
Moving all the strings into external xml files will allow doing this.

This is a low-priority feature

[PEMapModder]

Why not download strings from remote instead

[shoghicp]

@PEMapModder no

[PEMapModder]

Why? Since the strings will be downloaded along with the Git commit info at server init?

[miyu-desu]

Hello, I want to hangeul my pocket language with the titles of the titles.
There are a large number of Korean pocket users!
I don't know English very well those who choose the direction can be used to distribute jokesseumni....
Fly Omni see a lot of questions many people who can't speak English....
So I pocket Mine Korean. May I ask you, the distribution....

Here's your download link.
pocketmine.f4m.kr

If there is a download error, please look at the 1.0.1.

[hiilikewiki]

@windowsCreeper Please use the new PMMP