Ticks: when labels override is provided, don't render labels set to null
Bug: when providing a negative value for the ticks distance, the browser crashes
Merge pull request #81 from Learnosity/update/generateFixedTicks

Ticks: when labels override is provided, don't render labels set to null
Merge pull request #82 from Learnosity/fix/ticksWithNegativeDistance

Bug: when providing a negative value for the ticks distance, the browser crashes
unsuspendUpdate: Only update if isSuspended=true
Work on improved plotting
New curve plotting algorithm
Function plotting
Bug fix polygon: label was not shown after showElement() if visible==false
Using the old plotting algorith again. The new one wil be developed in a new branch.
newplot: first implementation of recursion
newplot: Append points to the list only once.
work on newplot
Fix slopetriangle issue mentioned in #79
newplot: Add a smoothness test.
Newplot: more fine tunings
Newplot: next version using distances instead of Newton-Cotes
Newplot: vertical asymptotes
Newplot: cusps
Newplot: addAsymptote()