Make sure new teams start with an unique name

Names of new or copied game schemes are now unique

Rework weapon scheme handling in frontend and fix a couple of bugs There were many oddities in weapon scheme editing which are fixed now: * When you left the weapon scheme editor, everything flashed briefly * When you leaft the weapon scheme editr, the weapon scheme selection always reverted to Default. Very annoying * Clicking on New or Copy now instantly creates and save the new weapons set