moved plugin translations to core


git-svn-id: http://dev.piwik.org/svn/trunk@7714 59fd770c-687e-43c8-a1e3-f5a4ff64c105
plugin doesn't provide language files anymore


git-svn-id: http://dev.piwik.org/svn/trunk@7715 59fd770c-687e-43c8-a1e3-f5a4ff64c105