lualoader: Add reload-conf loader command

This command will trigger a reload of the configuration from disk. This is
useful if you've changed currdev from recovery media to local disk as much
as I have over the past ~2 hours and are tired of the extra keystrokes.

This is really just a glorified shortcut, but reload-conf is likely easier
to remember for other people and does save some keystrokes when reloading
the configuration. It is also resilient to the underlying config method
changing interface, but this is unlikely to happen.

MFC after:	1 week

stand/lua/cli.lua

@@ -125,6 +125,10 @@ cli['boot-conf'] = function(...)
 	core.autoboot(argstr)
 end
 
+cli['reload-conf'] = function(...)
+	config.reload()
+end
+
 -- Used for splitting cli varargs into cmd_name and the rest of argv
 function cli.arguments(...)
 	local argv = {...}

stand/lua/cli.lua.8

@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 31, 2018
+.Dd September 13, 2019
 .Dt CLI.LUA 8
 .Os
 .Sh NAME
@@ -82,14 +82,27 @@ As of present, the
 module by default provides commands for
 .Ic autoboot ,
 .Ic boot ,
+.Ic boot-conf ,
 and
-.Ic boot-conf.
-In all three cases, the
+.Ic reload-conf .
+.Pp
+For
+.Ic autoboot ,
+.Ic boot ,
+and
+.Ic boot-conf ,
+the
 .Xr core.lua 8
 module will load all ELF modules as-needed before executing the equivalent
 built-in loader commands.
 All non-kernel arguments to these commands are passed in the same order to the
 loader command.
+.Pp
+The
+.Ic reload-conf
+command will reload the configuration from disk.
+This is useful if you have manually changed currdev and would like to easily
+reload the configuration from the new device.
 .Ss Exported Functions
 The following functions are exported from
 .Nm :