#618: remove unused code in sparsity_internal
#618 supress maybe-uninitialized warnings
#618: suppress maybe-uninitialized warnings in swig
#618 comment out unused variables in QPOases
#618: add -Wextra -Wno-unused-parameter
#618: commented out more unused variables in QPOases
Merge remote-tracking branch 'origin/develop' into release-1.9.0