Changed indenation of examples to 4 space, to be consistent with the whole library
Starte implementing bar style (showing top surface already)
Side surfaces of bars being drawn now (still depth ordering issues to fix)
Fixed depth ordering when using perspective
Fixed depth ordering without perspective
Some minor fixes and code sanitizing
Updated docs and playground
Replaced option `barWidth` with `xBarWidth` and `yBarWidth`. When undefined, the barwith is automatically calculated from the distance between the data points
Some fixes in depth calculation of bar surfaces
Implemented option 'bar-size'
Released Graph3d 1.3
Moved how to release file from wiki to a readme file