Webdave normally gives access to a cloud version of a file from a local computer.  However, it is also possible to set up a 2-way sync over webdav, using either of the following 2 programs; one of which is paid and the other free.

http://www.re.be/webdav_sync/index.xhtml
works from the command line using Java (free)

http://www.pincette.biz/davbox/index.xhtml
a paid version costing 15 euros (15 day trial).