remove osg, add glow, glm #40

compiling, no draw call yet
create glow window
use glfw directly instead glowwindow #40
add keyCallback to main.cpp. Pressing ESC now ends the game. #40
fix glowutils package-adding in CMakeLists.txt #40
replace std::err messages with glow::fatal. #40

glow output:
* glow::info()
* glow:: debug()
* glow::warning()
* glow::critical()
* glow:: fatal()

see https://github.com/hpicgs/glow/blob/master/include/glow/logging.h
add F5 Key for reloading... does nothing at the moment. #40
add version check and output at start. #40
add error callback. #40
add FindGLEW.cmake to resolve GLEW finding issues. #40
add proper initialization of GLEW in main.cpp. #40
add GLOW initialization (which does GLEW init for us). #40
add simple eventHandler to Game class. #40
change soundmanager to use glow logging #40
add (yet empty) Navigation and glowutils::Camera. #40
globally disable some warnings caused by glm and glow for now #40

glm: not standard extensions
glow: exporting std containers (which have no dll interface)
add basic plain drawing #40
set elements, render terrain with lighting and material #40
draw particles #40
pass the "terrain" to physx #40