Merge pull request #284 from stefanofornari/master

Refactoring constructor and draw accordingly to discussion in item #273
allow to change the event in the triggered event handlers
improved groupMinHeight feature
adding the documentation for groupMinHeight
adding the documentation for groupMinHeight
Merge pull request #288 from sapeish/master

allow to change the event in the triggered event handlers
Merge pull request #290 from sapeish/groupMinHeight-feature

Group min height feature
Updated changelog
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