* Fluid compilation: Inverse the compile flag from DISABLE_ELBEEM to WITH_MOD_FLUID for consistency. (scons/cmake)
* Use WITH_BF_FLUID in your user config (scons)
* Add support for scons to disable build with Decimate and Boolean modifier.
(WITH_BF_DECIMATE and WITH_BF_BOOLEAN)
* where_is_object_time was called for every effector evaluation only to determine the object velocity in some rare cases.
* Calculating the effector velocity is now done in the effector precalculation stage.
* Removing this makes the code thread safe and also should give some nice performance boosts when simulating a lot of points.
* Thanks to MiikaH for noticing this problem.
- use NULL rather then 0 where possible (makes code & function calls more readable IMHO).
- set static variables and functions (exposed some unused vars/funcs).
- use func(void) rather then func() for definitions.
* Greetings from farsthary: particle rotation is now taken into account for particle effector direction.
** This gives all kinds of new possibilities as he shows in his blog http://farsthary.wordpress.com/2011/02/08/vortex-particle-simple-tut/.
**The only modification I made to his patch was to use the actual rotated particle direction as the effector direction as this defaults to the particle velocity vector, so no actual new options are needed.
* I also added an "effector amount" setting for particle effectors so that only a part of the particles can be considered as effectors. This makes it possible to create simple "farsthary vortexes" with only one particle system.
* Also some tiny reorganization of the falloff min/max values for a nicer ui.
- removed deprecated bitmap arg from IMB_allocImBuf (plugins will need updating).
- mostly tagged UNUSED() since some of these functions look like they may need to have the arguments used later.
* Particle collision with size was broken since raytrace optimizations by jaguarandi, now the collision code falls back to old slower method when the collision ray has a radius.
* Single goal/avoid object now works for boids.
* Some tiny improvements on collision avoidance for boids.
problem is that where_is_object is being called from multiple threads
but is not thread-safe, added a note about this problem, this commit
only solves the crash. Also remove the pushdata/popdata mechanism
that was being used here, using this kind of system is bound to give
problems with threading.