So in fact one needs to first add his/her public key into Account Settings \ SSH Settings (here at the time of this writing.)
Then this:
rsync -avP -e ssh /path/to/your/release/folder
mksd@frs.sourceforge.net:/home/frs/project/openmrs/releases
No trailing slashes on either end, and replacing ‘mksd’ if you’re not me 
To be clear with no trailing slashes on either end, folder will be copied into releases.
@wyclif, regarding your comment on Confluence. How do I run the SQL differences between 2.1.0 and 2.1.1?