Creation date for files uploaded are not respected

[alfh]

There seems to be a bug in the seadroid related to uploading of files.

When I upload a file from seadroid, the actual creation date of the file does not seem to be sent to the server, so the server just sets "now" as create date.

To me, the API2 on the server side does not seem to have support for passing on a file creation date on "upload" API call.
If the API2 is missing that functionality, we should raise an issue on the seafile project, and when that issue has been resolved, the seadroid should be changed to pass along that info to the server side.