Add alternative views in serverbrowser and improve favourites

Alternative views in the serverbrowser are implemented with use favourites.
Categories (names) of favourite servers, which will be displayed on the
views, have to be included in "serverbrowseraltviews" alias (accessible
in menu).
Switching between views is possible with use Alt + Mouse wheel and
Alt + Up/Down (or eventually "[" and "]", if they are dedicated keys
on your keyboard).

The commit also:
1. adds MATCH category to favourites;
2. shows category name in settings of favourites;
3. shows weights in serverbrowser instead of favourites image,
when showweights = 1;
4. cleans up some tabs.

source/src/menus.cpp

@@ -1092,12 +1092,14 @@ bool menukey(int code, bool isdown, int unicode, SDLMod mod)
             case SDLK_UP:
             case SDL_AC_BUTTON_WHEELUP:
                 if(iskeypressed(SDLK_LCTRL)) return menukey(SDLK_LEFT, isdown, 0);
+                if(iskeypressed(SDLK_LALT)) return menukey(SDLK_RIGHTBRACKET, isdown, 0);
                 if(!curmenu->allowinput) return false;
                 menusel--;
                 break;
             case SDLK_DOWN:
             case SDL_AC_BUTTON_WHEELDOWN:
                 if(iskeypressed(SDLK_LCTRL)) return menukey(SDLK_RIGHT, isdown, 0);
+                if(iskeypressed(SDLK_LALT)) return menukey(SDLK_LEFTBRACKET, isdown, 0);
                 if(!curmenu->allowinput) return false;
                 menusel++;
                 break;