Improving Independents

[NTJedi]

Some issues I hope are addressed with Dominions_3 for the independents:

1) Allow independents to patrol castles and break sieges.
#patrol and #break siege would give more options for map makers.

2) Allow assassin independents to remain hidden and then assassinate enemy commanders which have recently moved into the province. I recommend adding #hidden and #assassinate.

3) Create an option during game setup where fleeing independents retreat into neighboring independent provinces. Since it's an option the previous method will still be available as well.

4) Create a new #random_move which instructs this group of independent to randomly travel into another nearby province owned by independents. Another new option for map makers.