removeSimpleEquations is slow on large models

[Francesco Casella]

The default implementation of removeSimpleEquations in the back-end is slow and scales badly with the system size.

A new implementation is available by selecting --removeSimpleEquations=new which performs much better. However, it is still incomplete (e.g., it doesn't handle arrays), and still has some bugs (some alias variables getting set to zero instead of the correct variables).

The new implementation should be completed and made the default. Besides the usual testsuite managed by GitHub/Hudson, when testing it I would recommend to also check out the performance with the ScalableTestSuite library

[Martin Sjölund]

Milestone renamed