This change means there can now be different translations for the same
english string depending on the context. It is based on gettext msgctxt feature.
There is a new macro _c(msg, ctxt) that should be used instead of _(msg) in
the source code when we want to add a context to the message. For the
moment I have added contexts to only one message ("None") so that I could
test the changes. Context could be added also to get shorter translations when
GUI is in 1x mode.
I have also added back the fuzzy option to msmerge since it is useful when
adding contexts to populate the translations for the new contexts.
svn-id: r52308
The GUI now uses the content of the Language field from the po file
header if it is present and not empty for the language selection
PopupWidget. If not present it uses the file name as before (e.g.
ru_RU).
Also update all the translation template and all the translation files.
svn-id: r51542
