FMT updates: k-nearest, freeSpaceVolume estimated through sampling results
FMT: freeSpaceVolume merge conflict
Heurisics collision check caching added and code improvements
Doc improved
style fixes
TODO included and *& changed to **
minor fix
kNN sorted check
Merge branch 'master' of http://github.com/ompl/ompl into FMT_updates
Merge pull request #41 from jvgomez/FMT_updates

FMT updates: improves code, heuristics, kNN and collision check caching