(svn r10897) [NewGRF_ports] -Cleanup: Removed superfluous comments.

(svn r10896) [NewGRF_ports] -Change: Redesign of seaplaneport.grf to allow access to terminal 1 even when runway is in use.
Changes can also be ported to Small Airport.

(svn r10895) [NewGRF_ports] -Fix: Only visually leave the hangar if the aircraft can successfully move to its chosen destination. Enables the decision to proceed to based on block reservations in the hangar commands, not in code.

(svn r10893) [NewGRF_ports] -Fix: Ensure coloured & masked selections disabled on exit of airport_gui.
-Fix: If no airport is selectable on change of airport class, ensure highlight is only a 1x1 square.

(svn r10891) [NewGRF_ports] -Change: Added ramp and 2 jetties to seaplaneport.grf. (Thanks to 0004tom).
-Change: modified movement to move around jetties, and FSM for better block handling.
-Change: Modified prop 20 (temporarily) to allow all small aircraft, for testing.

(svn r10889) [NewGRF_ports] -Feature: Colour of highlight for FSMs with placement masks shows Green for land tiles, and Blue for water tiles.

(svn r10885) [NewGRF_ports] -Fix: Prevented passengers from being squished on the bulkhead.
Forgot to slow aircraft down gracefully on landing... 500mph->31mph in 50yds ;)

(svn r10884) [NewGRF_ports] -Change: clarified CanReserveBlocks in comments.

(svn r10883) [NewGRF_ports] -Fix: crashing aircraft caused deadlocking of the airport; they didn't release their owned blocks when the aircraft was finally destroyed.

(svn r10882) [NewGRF_ports] -Feature: Real World Airports. First draft, including just LaGuardia for the moment.
2 crossing runways. 4 terminals. 1 heli-landing pad (but unloads passengers at terminals).