Variables are never removed from _varMap

[joshuahhh]

Variables are added to _varMap (in Solver) when constraints are added, but they are never removed, even if all the constraints that refer to them are removed. This could cause a memory leak in some situations.

[IjzerenHein]

Alright, thanks for pointing this out. I'll take a closer look at this in two weeks or so.
cheers