release plugin doesn't tag correctly with svn+ssh when remote and local username don't match

svn is very stubborn about this. Basically you have to have the value in <developerConnection> match the url used to check it out.

Things that will fail:

• if you pass in a different username to --username, it is not passed on to ssh
• if you specify a username in the ssh command it works, as long as the URL is the same in both. svn+ssh://bporter@foo/... is considered a different repository to svn+ssh://foo/... even if I am bporter

I think we can take a couple of steps:

• for svn+ssh, put the username in the URL instead of passing --username
• possibly check the current checkout (svn info) and derive the tag location from that, ignoring the local checkout OR if they don't match, relocate the local checkout to that of developerConnection
• use javasvn instead