Undo change to SGVector<char>::display_vector.
Quadratic support for rest numerical hashed classes
Added display_vector() method to SGSparseVector for easier debugging.
Merge pull request #1311 from iglesias/develop

Disable temporarily buggy FactorGraph tests
Merge pull request #1310 from tklein23/display_for_sparse_vector

Added display_vector() method to SGSparseVector for easier debugging.
Merge pull request #1308 from tklein23/display_vector_char_revert

Undo change to SGVector<char>::display_vector.
Merge pull request #1309 from van51/feature/quadratic

Quadratic support for rest numerical hashed classes