Added Skip_Goals Command option

Also added --sg to the 4 test/postive files that needed it

see:

http://gsd.uwaterloo.ca:8888/question/1059/add-a-parameter-to-skip-code-generation-for
Fixed typo in help message from previous commit
improved help message for `--skip-goals`
Merge branch 'WarningFixes' into i253
Merge pull request #33 from gsdlab/i253

I253