Mobile Services: Fix job update command

This log improves the update command:
- Fixes a bug that didn't allow you to convert the job to on demand
using -u none
- Fixes a bug that required specifying the --status option when used
- Makes using the --startTime flag optional when switching an on demand
job to be scheduled
Fix jsHint issues
Address code comments
Merge pull request #715 from phvannor/job-update-fix

Mobile Services: Fix job update command