Continue to upload files if a file is rejected (Uploaded content is unacceptable)

[gabldotink]

Trying to upload a full directory, with multiple levels and arbitrary files. The file ./archive/adobePhotoshopPatterns/Color Paper.pat is rejected after uploading, with the error:
error uploading /archive/adobePhotoshopPatterns/Color Paper.pat: Uploaded content is unacceptable. - image file has non-image contents: application/octet-stream, try one of these extensions: .obj .dll .bin .a .o .so .exe .deploy .msu .msp
, and then exits.

I don't know how many files will be rejected like this. It's just a list of example files for various formats, including some very obscure ones, so tons of them are bound to get skipped. I'm fine with them being skipped, but it would be great if it kept going with the ones IA would accept.

Related to #490.

[jjjake]

I think the default behavior for this should stay the same, and we should add this as an --ignore-errors (or similar) option.

Thanks for taking the time to submit this issue, @gabldotink