Make BBCode placeholders more intuitive

[martinambrus]

Right now, BBCode parsing will load user, alliance, coordinates etc. from the number (id) given in the placeholder, such as [alliance0]blabla[/alliance0]. This should be made more intuitive by just providing [alliance]allianceName[/alliance] as a placeholder and the BBCode parser would auto-create a link to the actual "allianceName" alliance.