Merge from ReForm: Optimize MISolver::solve_multiple_rounding()

See merge request !56

* Avoid processing twice indices of values to round
* Replace the rounding set with a priority queue
* Remove unnecessary "old index" map
* Reformat MISolver.cc to conform to the style guidelines and add missing ; after DEB_* statements
* Remove MISolverT.hh
* Move private symbols to the cc file
* Improve code quality, formatting and const-correctness of IterativeSolverT
* Improve code quality and formatting for MISolver::update_solution

WIP REFORM-922 merge new sanitization

See merge request !55

Merge commit 'fd5a616e' into marinom/REFORM-922-merge-new-sanitization

* Consume Eigen from 3p
* Fix compilation warning
* Fix compiler warnings in AcceleratedQuadraticProxy.hh

Exact constraint satisfaction

See merge request !54

add improved method to collect the terms of the safe dot product to compute value of dependent variable