(svn r12891) [0.6] -Fix (r12868): breakdowns were broken and would cause vehicles to go slower than they should have been moving.

(svn r12892) -Fix: too many items in the vehicle toolbars were greyed out.

(svn r12890) [NewGRF_ports] -Change: Add comment to new function, and correct comment in old.

(svn r12889) [NewGRF_ports] -Change: Optimise before commit ;)

(svn r12888) [NewGRF_ports] -Fix: Rewrite of aircraft movement to correct shallow descents, which werent working correctly. Use of target_altitude variable for added clarity.
-Change: Helicopter speed in holding pattern specified.
-Change: Helicopter landing limited to a minimum of 65kmh
-Change: Helicopters only change height vertically when landing/taking off.
-Change: Helicopters fly 5 below same speed aircraft.
-Change: Helicopter descent position marked by Bit9=1 in amd->flags.
-Change: Updated Spec & .grfs to use Bit9=1 for heli descent position. (WIP)

(svn r12887) [NewGRF_ports] -Fix: When upgrading an airport, remove the existing FSM first.
-Add: Added function to RemoveFSMSpecFromStationList when the index is unknown.

(svn r12886) [NewGRF_ports] -Change: Added test for IsInFlight to detect if an aircraft is flying between airports, or is in the main body of the FSM.

(svn r12885) [NoAI] -Add: added AISubsidy and AIEventSubsidyNNN (Yexo)

(svn r12884) [NoAI] -Fix r12880: make doxygen happy by commenting on all the typedefs.. boy, what are those comments explaining!

(svn r12882) -Fix (r12764): the check for missing header files could find more files than needed