Allow for create to return undef

This happens when SoftwareResult::create fails to create the result
because another process has already created it.  Then
SoftwareResult::get_or_create will look for and find the already created
result.
Indentation
Remove e-mail and sleep when removing invalid lock
Merge pull request #90 from davidlmorton/AT-624-second-attempt

Allow for create to return undef
Remove outdated comment
Remove env variable that is no longer needed
Merge pull request #93 from apregier/dont_wait_to_remove_bad_lock

Don't wait to remove bad lock