Adding module to purge unneeded Salesforce object map records.
added purge now button, modified purge process to iterate once per call instead of looping until all records were exausted. Added watchdog logging and code to back up data being purged. Purged records are written to .csv in files/sf_purge_backups
minor tweaks to log messages and comments
added comment explaining purge now function
Merge pull request #300 from JacksonRiver/6.x-3.0-object_map_purge_util

6.x 3.0 object map purge util