ensure any acces to those methods can be done on any connection from the event
manager without crash the applications. This way is not less consistent than the
previous where isServerConnection was defined on ClientConnection and so on...
Replace any isinstance() calls with a connection as parameter by call to the
attributes above. 


git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@1088 71dcc9de-d417-0410-9af5-da40c76e7ee4