Make Confluence localization a user specific option

Right now confluence localization settings can be set only on per-instance basis.

Confluence as an enterprise software, should expect, that companies are often international and multilingual. For this reason it would be great, if users could select from the available list of localizations the one that fits them the best. This could be done via the user profile settings.

I believe that most of the infrastructure for getting this done is already there, it should really be just about selecting the i18n property file based on user settings. This should make the feature relatively easy to implement.