Allow editing the default value.xml file

[erickok]

Original issue from https://code.google.com/p/android-php-translator/issues/detail?id=11

Reported by nikita.s.kozlov, Sep 29, 2010
It can be useful to be able to edit (correct) the default value.xml file.

In my case, I have chosen English as default language for my application, but I'm not a native English speaker so I have some error in the default .xml file and I will be happy if my contributors could help me to correct them through the web interface. :)

Choosing my native language as default won't help because we have english speaker contributors, so I won' be able to correct them through the web interface.