#11 JGlobus log4j control

[Jan Ploski]

For debugging purposes, it is useful to capture detailed logs from JGlobus sometimes - especially message exchanges on the control connection. It should be possible to turn such logging (to a specified file) on/off through a preference and to browse the log file's content (maybe we could reuse the log browser from Eclipse's TPTP project, but it might be an overkill).