add atom radius
add some colors, add few TODOs
add QString::SkipEmptyParts to split() used in parseBond()
add atom colors
add mesh paths and logics to use when USE_ASSIMP is undefined
fragment shader: normalize(color)
change to rotate model by using mouse buttons
add atom data (size, color) and initAtomData(), change atomColor() and
atomRadius() to use atomData.
fix crash
add projection methods(but comment out for now)
inverse zoom in/out direction in wheelEvent()