Consider quick start game mode

[GoogleFrog]

A mode, possibly enabled by default for skirmish and custom games, that gives player a starting base. A bit like the AoE 2 initial base modes. The trick would be to give people enough structures and units for them to get started and learn the structure of the game (eg a factory with a repeat queue), but not one that is overwhelmingly complicated .

[sprunk]

Duplicate of #5291 (at least implementationally)?