Use session-specific log where possible

[chrjohn]

For some error cases there only is a message logged to the general log. But it would be beneficial to see such errors in the session-specific log file.

Example where the SessionID is available but only the general log is used:

quickfixj/quickfixj-core/src/main/java/quickfix/mina/initiator/AbstractSocketInitiator.java

Line 185 in 9bdd8b8

log.warn("error during session initialization for {}, continuing...", sessionID, e);