devd based AUTOMOUNTER

[Ivan Klymenko]

> Hi,
> 
> I have been pretty busy lately because of boring things
> work/life stuff, but here is the new version, with more
> options of course and some bugs fixed, it now displays
> help when triggered as 'automount --help', at least a
> substitute of a man page ;)
> 
> I have a quastion, which devd(8) events should I 'catch'
> to enable CD automount? Is there an event for a CD being
> entered into the CD-ROM at devd(8)?
> 

Unfortunately, I spent a few days that would have to understand how it
is possible to detect the inserted CD-ROM with devd; but alas - the
only thing that detects changes in the drive CD-ROM - a :
sysctl kern.geom.conftxt

before inserting the disc:
kern.geom.conftxt: 0 DISK cd0 0 2048 hd 0 sc 0
...

after inserting the disc:
kern.geom.conftxt: 0 DISK cd0 4700372992 2048 hd 0 sc 0
...