Preprocessor for the TrustRegionMinimizer.

1. Base class for preprocessors.
2. A preprocessor for problems that will be solved using
   the trust region minimizer.
3. Added sanity tests to the program reordering options
   for Schur type linear solvers.
4. Tests for the TrustRegionPreprocessor.

Change-Id: I88cd926f0053bbbf2bd6b11e03ec55b8bf473cf1
7 files changed