On MSVC, casting i32 to i64 then multiplying gets compiled into a call
to __allmul, which is slow. Use the __emul intrinsic instead.
GCC 4.6+ appears optimise this case automatically and doesn't need any
special handling.
This reduces the cost of ComputeShortPath by about 50% (testing AI vs AI
on Oasis 01).
This was SVN commit r13873.
Support asynchronous path queries.
Allow escaping when stuck in impassable terrain tiles.
Split Update message in multiple phases, to cope with ordering
requirements.
Support automatic walk/run animation switching.
This was SVN commit r8058.
Add short-range vertex-based pathfinder.
Integrate new pathfinder into unit motion code.
Change obstruction system to get rid of circles, and differentiate
structures from units.
Make PositionChanged messages synchronous.
Try to prevent some accidental float->int conversions.
This was SVN commit r7484.
