Add RST version of gnt-job man page

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

man/gnt-job.rst

+gnt-job(8) Ganeti | Version @GANETI_VERSION@
+============================================
+
+Name
+----
+
+gnt-job - Job commands
+
+Synopsis
+--------
+
+**gnt-job** {command} [arguments...]
+
+DESCRIPTION
+-----------
+
+The **gnt-job** is used for examining and manipulating the job
+queue.
+
+COMMANDS
+--------
+
+ARCHIVE
+~~~~~~~
+
+**archive** {id...}
+
+This command can be used to archive job by their IDs. Only jobs
+that have finished execution (i.e either *success*, *error* or
+*canceled* jobs).
+
+AUTOARCHIVE
+~~~~~~~~~~~
+
+**autoarchive** {*age* | ``all``}
+
+Archive jobs by their age. This command can archive jobs older than
+*age* seconds, or alternatively all finished jobs can be archived
+if the string all is passed.
+
+CANCEL
+~~~~~~
+
+**cancel** {*id*}
+
+Cancel the job identified by the given *id*. Only jobs that have
+not yet started to run can be canceled; that is, jobs in either the
+*queued* or *waiting* state.
+
+INFO
+~~~~
+
+**info** {*id*...}
+
+Show detailed information about the given job id(s). If no job id
+is given, all jobs are examined (warning, this is a lot of
+information).
+
+LIST
+~~~~
+
+**list** [--no-headers] [--separator=*SEPARATOR*]
+[-o *[+]FIELD,...*]
+
+Lists the jobs and their status. By default, the job id, job
+status, and a small job description is listed, but additional
+parameters can be selected.
+
+The ``--no-headers`` option will skip the initial header line. The
+``--separator`` option takes an argument which denotes what will be
+used between the output fields. Both these options are to help
+scripting.
+
+The ``-o`` option takes a comma-separated list of output fields.
+The available fields and their meaning are:
+
+
+
+id
+    the job id
+
+status
+    the status of the job
+
+priority
+    current priority of the job
+
+received_ts
+    the timestamp the job was received
+
+start_ts
+    the timestamp when the job was started
+
+end_ts
+    the timestamp when the job was ended
+
+summary
+    a summary of the opcodes that define the job
+
+ops
+    the list of opcodes defining the job
+
+opresult
+    the list of opcode results
+
+opstatus
+    the list of opcode statuses
+
+oplog
+    the list of opcode logs
+
+opstart
+    the list of opcode start times (before acquiring locks)
+
+opexec
+    the list of opcode execution start times (after acquiring any
+    necessary locks)
+
+opend
+    the list of opcode end times
+
+oppriority
+    the priority of each opcode
+
+
+If the value of the option starts with the character ``+``, the new
+fields will be added to the default list. This allows to quickly
+see the default list plus a few other fields, instead of retyping
+the entire list of fields.
+
+WATCH
+~~~~~
+
+**watch** {id}
+
+This command follows the output of the job by the given *id* and
+prints it.