I would like to configure the import task to import new/updated content only or to import everything

I would like to configure the import task to import new/updated content only or to import everything so I have more flexibility in running the import.

Acceptance Criteria

1. Provide a UI element in the task configuration to enable or disable "Import content since last run"
   1. If this is enabled, import components newer than what was recorded in the delta files.
   2. If this is disabled, ignore delta files and import everything. Add/update the delta files with corresponding imported component info.

Notes

We may not need this functionality since deleting the each of the delta files from the .nxrm folder should cover the need to force a full rebuild. Until we know how often users need to do that, it's better to keep the UI simpler. Users shouldn't have to make a decision about whether to use delta importing or not, the system should be smart enough to handle it for them so they only have to choose where to import from/to. We may find that rather than introducing a checkbox we can get away with adding some additional logic to the system that handles the problem for the user, but we won't know until we know why users are doing full imports when they could be doing delta imports.