Enhanced AddImage/Video data location and upload.

[ifadams]

Is your feature request related to a problem? Please describe.

• Enabling AddImage/AddVideo command with a URL instead of blob, could enable new optimizations or usages.
• As described in AddImage using existing blobs #27 we may also want the capability of linking an existing images location to a "new" image entity.

Describe the solution you'd like

1. Metadata could be added while pointing to data at a remote location
2. Bulk uploads (e.g., remoteIP:videoDir/*.mpg) could be enabled (potentially in the background)
3. Uploads with filtering operations in the operation pipeline could be done efficiently (perform filtering at the data location, avoiding bringing over the data to the VDMS server only to drop it after the filter)
4. Be able to find an existing image and link it to the appropriate metadata entity for future locations/relocation.