REWRITE fix minor typo in Equalities namespace
DisjointSets: add new operator==, != and representative() functions
Equalities: add silly compiler fixes
DisjointSets: Add operator << for ostream
DisjointSets: fix names of tests
DisjointSets: fix mistakes in DisjointSets::==
Equalities: add clone() function
Equalities: change from sem_elem_t to Guard