Make filename of temporary files for script steps configurable

[drbeka]

We test rundeck with HP tandem as remote nodes.
In executing inline scripts as workflow step rundeck generates long filenames that are unusable on tandem, because only filenames with less than 9 characters and without "." are allow
ed (the script will be saved with first 8 characters).
We would like the possibility to get filenames with less than 9 characters or the possibility to configure, that for example the job.execid can be used as temporary filename.