virsh: add aliases 'boot', 'stop', and 'restart'

https://bugzilla.redhat.com/show_bug.cgi?id=873344 suggested that
the grouping 'boot', 'shutdown', 'reboot'; as well as the grouping
'start', 'stop', 'restart'; might be easier to remember than the
current mix of 'start', 'shutdown', 'reboot'.

Also, touch up the wording of 'reboot' to be more accurate.

* tools/virsh-domain.c (domManagementCmds): Add other command names.
* tools/virsh.pod (start, shutdown, reboot): Document the aliases.

tools/virsh-domain.c

@@ -8298,6 +8298,7 @@ const vshCmdDef domManagementCmds[] = {
     {"blockjob", cmdBlockJob, opts_block_job, info_block_job, 0},
     {"blockpull", cmdBlockPull, opts_block_pull, info_block_pull, 0},
     {"blockresize", cmdBlockResize, opts_block_resize, info_block_resize, 0},
+    {"boot", cmdStart, opts_start, info_start, 0},
     {"change-media", cmdChangeMedia, opts_change_media, info_change_media, 0},
 #ifndef WIN32
     {"console", cmdConsole, opts_console, info_console, 0},
@@ -8351,6 +8352,7 @@ const vshCmdDef domManagementCmds[] = {
     {"numatune", cmdNumatune, opts_numatune, info_numatune, 0},
     {"reboot", cmdReboot, opts_reboot, info_reboot, 0},
     {"reset", cmdReset, opts_reset, info_reset, 0},
+    {"restart", cmdReboot, opts_reboot, info_reboot, 0},
     {"restore", cmdRestore, opts_restore, info_restore, 0},
     {"resume", cmdResume, opts_resume, info_resume, 0},
     {"save", cmdSave, opts_save, info_save, 0},
@@ -8367,6 +8369,7 @@ const vshCmdDef domManagementCmds[] = {
     {"setvcpus", cmdSetvcpus, opts_setvcpus, info_setvcpus, 0},
     {"shutdown", cmdShutdown, opts_shutdown, info_shutdown, 0},
     {"start", cmdStart, opts_start, info_start, 0},
+    {"stop", cmdShutdown, opts_shutdown, info_shutdown, 0},
     {"suspend", cmdSuspend, opts_suspend, info_suspend, 0},
     {"ttyconsole", cmdTTYConsole, opts_ttyconsole, info_ttyconsole, 0},
     {"undefine", cmdUndefine, opts_undefine, info_undefine, 0},

tools/virsh.pod

@@ -1124,11 +1124,14 @@ If I<--config> is specified, affect the next boot of a persistent guest.
 If I<--current> is specified, affect the current guest state.
 
 =item B<reboot> I<domain> [I<--mode acpi|agent>]
+=item B<restart> I<domain> [I<--mode acpi|agent>]
 
-Reboot a domain.  This acts just as if the domain had the B<reboot>
-command run from the console.  The command returns as soon as it has
-executed the reboot action, which may be significantly before the
-domain actually reboots.
+Restart a domain.  Depending on the hypervisor, this may request a
+shutdown followed by a fresh boot, rather than triggering a software
+reboot.  The command returns as soon as it has requested the reboot
+action, and depending on the guest, there may be a significant delay
+before the domain actually reboots, or the request might even be
+ignored.
 
 The exact behavior of a domain when it reboots is set by the
 I<on_reboot> parameter in the domain's XML definition.
@@ -1523,6 +1526,7 @@ be hot-plugged the next time the domain is booted.  As such, it must only be
 used with the I<--config> flag, and not with the I<--live> flag.
 
 =item B<shutdown> I<domain> [I<--mode acpi|agent>]
+=item B<stop> I<domain> [I<--mode acpi|agent>]
 
 Gracefully shuts down a domain.  This coordinates with the domain OS
 to perform graceful shutdown, so there is no guarantee that it will
@@ -1543,6 +1547,8 @@ can specify C<acpi> or C<agent>.
 
 =item B<start> I<domain-name-or-uuid> [I<--console>] [I<--paused>]
 [I<--autodestroy>] [I<--bypass-cache>] [I<--force-boot>]
+=item B<boot> I<domain-name-or-uuid> [I<--console>] [I<--paused>]
+[I<--autodestroy>] [I<--bypass-cache>] [I<--force-boot>]
 
 Start a (previously defined) inactive domain, either from the last
 B<managedsave> state, or via a fresh boot if no managedsave state is