Re-applying the refactoring from the 859-schedulable-permissions because I screwed up that branch.
Fix for #890 in Github.
Resetting schedulable table only if necessary.
Moving some test code from the install script test to the settings manager test, since we are not scheduling the master jobs from the install script now.
(Strangely, I get a compilation error saying that there is no CronJobDetail in CronTrigger. Weird, specially since it's the same exact query we had before. Let's see if it passed build.)
A file needs to be in version 29 or higher to see the CronJobDetail relationship to CronTrigger.
Te master scheduled jobs now are being set when the settings page loads.
Aborting the "newer" scheduled jobs to make sure they get re-scheduled from the settings page.
Centralizing the scheduled jobs names in one class.
Oops.
Aborting also the scheduled jobs with the new name on uninstall.
Merge dev into feature/859-schedulable-not-supported
Merge pull request #906 from SalesforceFoundation/feature/purge-on-delete-true

Change back to purgeOnDelete="true"
Merge branch 'dev' into feature/859-schedulable-not-supported
Merge pull request #895 from SalesforceFoundation/feature/859-schedulable-not-supported

Feature/859 schedulable not supported
Merge dev into feature/purge-on-delete-true