implemented the mode for robots so that darken tracks is correct now
cleaned up unused classes
Plants: added support for multiple types of plants, deriving from Plant
Merge branch 'master' into abe/work
emoji are now seperated into planter, normal and enraged
emoji are now seperated into planter, normal and enraged
gitignore .DS_Store and build-tmp
gitignore .DS_Store and build-tmp
bots now leave two tracks instead of one
updated README
new 3D plant
Use copy constructors instead of cloning
Add link to gh-pages
Merge branch 'abe/work'

Conflicts:
	botsBehaviour/botsBehaviour.pde
Add comments about optimization
Optimized new plant. Calculates points first, then only renders

Could be further optimized by caching the finished (non growing) leave
as a complete PShape that includes colors, as shown in listing 4.1 of
http://processing.org/tutorials/pshader/
Plant optimization. Grown plant is not recalculated, just sent to the gpu.

Also general aesthetic improvements.