Added method "is_sorted()" to SGVector
* plus unit tests for SGVector::qsort() and SGVector::is_sorted().
Merge pull request #1507 from tklein23/sgvector_is_sorted

Added method "is_sorted()" to SGVector
minor fixes in GP framework
Merge pull request #1511 from votjakovr/feature/gp_refactoring

Minor fixes in GP framework