With the initremote parameters "encryption=pubkey keyid=788A3F4C".
/!\ Adding or removing a key has NO effect on files that have already
been copied to the remote. Hence using keyid+= and keyid-= with such
remotes should be used with care, and make little sense unless the point
is to replace a (sub-)key by another. /!\
Also, a test case has been added to ensure that the cipher and file
contents are encrypted as specified by the chosen encryption scheme.
8293ed619f