Add altering pages in serverbrowser and improve favourites

Altering pages in serverbrowser are implemented with use favourites.
Categories (names) of favourite servers, which will be displayed on the
pages, have to be included in "serverbrowseraltpages" alias (accessible
in menu).
Switching between pages is possible with use ALT + mouse wheel or
"[", "]" keys.

The commit adds also MATCH category to favourites, shows category name
in settings of favourites and cleans up some tabs.