Got git annex export working to webdav and rsync special remotes. Tested exporting to the Internet Archive via S3, and to via webdav. Both had little weirdnesses in their handling of the protocols, which were worked around, and it's quite nice to be able to export trees to those services, as well as Amazon S3.

Also added connection caching for exports, so S3 and webdav exports only make one http connection, instead of one per file.

Had to change the format of git-annex:export.log; the old format didn't take into account that a repository can export to several different remotes.

Today's work was supported by the NSF-funded DataLad project.