i18n support

[calidion]

currently manifest only support a string for key name and short_name.

I would like to suggest, they use i18n based object to represent i18n strings.

for example:

from

{
name: "An Angular Based Application"
short_name: "angular"
}

to

{
name:  {
"en" : "An Angular Based Application",
"zh" : "一个基于角度的程序",
"ja" : "角度ベースのアプリケーション",
}，
short_name: {
"en" : "Angular",
"zh" : "角度",
"ja" : "角度",
}
}

[fallaciousreasoning]

I believe there was some discussion about doing something like this, but I can't find it in any of the other issues.

Related:
#323 #334 #335 #336 #337

From the sounds of things, the resolution on those issues was to serve a different manifest based on the Accept-Language? I guess that doesn't work for changing the language on the OS though.

[fallaciousreasoning]

Ah, I think this was the issue I wanted: #208

This idea, along with some others are discussed a bit there. The resolution seemed to be "Let's wait for a bit and see what problems come up", so I'll leave this open.

[fallaciousreasoning]

Note #211 is almost identical.

[calidion]

default_locale or languages is not necessary for the locale devices has defined their locales.
make all strings i18ned.

[marcoscaceres]

closing as duplicate of #676