Resolve "TSModelBuilder should support merging empty bins"

Release notes

An intelligent merging was implemented to automatically merge bins such that no bins are left empty. Usage:

<mergeBins.minimalBinContent=0, mergeBins.minimalSummedBinContent=1> % these are default
<mergeBins=true, mergeBins.hardBorders={7,14,21,28,35,42,49,56,63,70,77,84,91,98,105,112,119,126,133}>

Details

Thanks to Remco for doing the bulk of the work!

Closes #47 (closed)