abstract superclass Drawable, also for ParticleDrawable, adding boudingbox to all drawables #92
add bounding box rendering step, shader unfinished #92
draw bounding boxes as grid #92
toggle drawing of "debugstep" with key F1 #92
Merge branch 'project_reordering' into particleCollision_92

Conflicts:
	CMakeLists.txt
	src/rendering/drawable.cpp
	src/rendering/renderer.cpp
	src/ui/eventhandler.cpp
	src/ui/hand.cpp
	src/world.cpp
implement basic bbox based collision check #92
perform collision check only 2x per second #92
create lua script for the collision handling #92
get and visualize the particle boundingbox intersection volumes #92
nicer boxes with back face culling #92
improve bounding box based collision detection #92

good result, if only a single set of colliding particles exists between two particle groups
add more int types to supported lua parameter types
particleGroup: release particles in bounding box, create particles without velocities, use std::vector #92
first element reaction: lava+water=bedrock #92 #63
improve bounding box based collision, again #92
Merge remote-tracking branch 'origin/master' into particleCollision_92
Merge branch 'libelemate_tests_114' into particleCollision_92

Conflicts:
	libelemate/particles/particlegroup.cpp
	libelemate/particles/particlegroup.h
	libelemate/rendering/particledrawable.cpp
	libelemate/rendering/particledrawable.h
	libelemate/terrain/terrain.h
	libelemate/ui/eventhandler.cpp
	libelemate/ui/hand.cpp
	shader/CMakeLists.txt
	src/CMakeLists.txt
Merge remote-tracking branch 'origin/libelemate_tests_114' into particleCollision_92
basic tree based collision check working #92
using namespaces glm, glowutils in particlecollision.cpp #92