Added gen_sudoers.sh script to generate a sudoers file for perforce OSUSER.
This generates a more secure limited sudoers file.
Previously, adding a sudoers entry for the OSUSER (usually 'perforce') was done only by the Helix Installer. In the Helix Installer variant, a single "one-size-filts-all" sudoers file was used, with the following characteristics:
* The instances for Helix Core services were referenced with a '*' wildcard to match all SDP instances, which has since been determined to introduce a vulnerability. In this new script, the wildcard is replaced with separate entries for each SDP instance.
* There were entries for all known paths of utilities like lslocks, setcap, and getcap. This new script generates the correct path valid for the current machine.
With this change, the functionality will be available in the SDP directly. This new gen_sudoers.sh script can be called by mkdirs.sh directly to update the sudoers file each time a new SDP instance is added, if the new '-fs' (full sudo) or '-ls' (limited sudoers) entries are used. There is no change to the default behavior of mkdirs.sh; only a change if new options are utilized.
This script comes with docs and examples for the new script as well as doc changes for mkdirs.sh. (Also added missing documentation for the '-no_enable' option).
Further changes needed:
* Add doc reference in SDP_Guide.Unix.adoc