change 'make all' targets to override new default target in clawutil
Added regression tests to examples/.  Requires new code in clawutil.
Merge pull request #56 from rjleveque/make_all_override

change 'make all' targets to override new default target in clawutil
Merge remote-tracking branch 'clawpack/master' into add-setaux-flag-mask
Array extents bug fix