Enhancement plus minor bug fixes.

This patch to globus_gatekeeper.c makes the gatekeeper rotate its logfile
on reception of SIGUSR1: the name of the current file is given an extension
".$timestamp.$seqnr" where "$timestamp" has "YYYYMMDDHHMMSS" format and
"$seqnr" is 0 when the gatekeeper is started and incremented each time the
signal is sent.  The file is closed and a fresh standard logfile is opened.
The signal would be sent by a cron job whenever the logfile has reached a
certain size and/or once per day/week/...

Job accounting info is written to an accounting file (= gatekeeper logfile
by default), which is also rotated.

For each job, the accounting information is of the following format
(see corresponding patch for the jobmanager):

----------------------------------------------------------------------
JMA YYYY/MM/DD HH:MM:SS GATEKEEPER_JM_ID <ID> for <DN> on <IP-addr>
JMA YYYY/MM/DD HH:MM:SS GATEKEEPER_JM_ID <ID> has GRAM_SCRIPT_JOB_ID \
 <JOB_ID> manager type <type>
JMA YYYY/MM/DD HH:MM:SS GATEKEEPER_JM_ID <ID> JM exiting
----------------------------------------------------------------------

The <ID> string has this format:

    YYYY-MM-DD.HH:MM:SS.<PID>.<SEQ>

where <PID> and <SEQ> are left-padded with zeroes to have 10 digits.
<PID> is the PID of the gatekeeper, <SEQ> is request sequence number
(incremented per connection).  The <ID> string is obtained from the
"GATEKEEPER_JM_ID" environment variable defined by the gatekeeper.
The second JMA line allows the job's <DN> and originating host to be
linked to the job's accounting information recorded by the batch system.

A corresponding patch for the LSF job manager script supplies a job
summary before the "JM exiting" line, of the following format:

----------------------------------------------------------------------
JMA YYYY/MM/DD HH:MM:SS GATEKEEPER_JM_ID <ID> summary:
<output of "bacct -l <JOB_ID>">
JMA -- end of summary
----------------------------------------------------------------------

For other batch systems such a job summary is not yet available.
The accounting information is written to the file descriptor named by
the "GATEKEEPER_ACCT_FD" environment variable defined by the gatekeeper;
if the variable is not set, or if the descriptor cannot be written to,
the accounting information is discarded.

By LCG (Maarten.Litmaath@cern.ch).