[Plugins] Make Plugins have lang.xml files as well

[Chris59]

Would like to see also the plugins have their own , is bad we can't. ex: I run 2 board and buy a big plugin with huge amount of langstrings 
and use it on both boards. then I must translate it twice .... that sux really  

Hope to see some changes about this in future .... 

Other then that I say Thanks to all Developers for your superb
works with apps and plugins, IPS Rocks and 10 stars to all of u