Gettext localization

Should be fairly easy to switch to Gettext by mapping each component to a separate Gettext "message domain".

Something like the following:

// Inform gettext about a new localization domain when a component is loaded
bindtextdomain('net.nemein.discussion', MIDCOM_ROOT.'lib/net/nemein/discussion/locale')

// Show localized message
echo dgettext('net.nemein.discussion', 'new reply');

For backwards compatibility, we should be able to wrap this quite easily with $_MIDCOM->i18n->get_string($stringid, $component = null)

Then we need to consider how to extract strings with xgettext if a component uses this wrapper instead of good plain old gettext() function.

Advantages with using Gettext:

• Performance (probably, at least when using PHP's gettext extension that is written in C)
• Possibility to edit translations using an external translation client
• Compatibility with translation workflows used with all other free software projects
• Possibility to separate plural and singular phrases in localications
• Possibility to remove at least some code from MidCOM