Apply patch #3360. Fixes bug #19862 and bug #16220

(Browse SVN revision 55454)

Would be worth checking to see if this patch also addresses bug bug #16220

Issue solved. Moved some code around in the change control stuff in turn_info::process_network_data() so that it runs even if make_human() was called on the affected team before and added a change_controller() call in the switch statement, under the "Replace with local player" case (I wonder why it wasn't there in the first place).

(file #16000)

This patch fixes #19862 and a bunch of other (possibly not yet spotted) bugs related to transferring control of sides in mp games.
The bugs:

• droiding your side make you become an observer
• undroiding your side during the turn of someone else results in your messages appearing in that side's color on your client (a.k.a. bug #19862)
• when passing control of a side to a player the gui isn't properly updated
• droiding/undroiding a side during that side's turn would make the actions of that side visible for everyone for that turn

And the respective fixes:

• modified is_observer() to return true only if there're no human or human_ai sides
• solved as a side effect of fix 1
• added the appropriate function calls in turn_info::process_network_data()
• removed unnecessary update_gui_to_player() call at playmp_controller.cpp:492