[PATCH] OsdSynch.c modernization

I have rewritten sys/dev/acpica/Osd/OsdSynch.c to match the modern 
ACPI-CA and -CURRENT:

http://people.freebsd.org/~jkim/acpica/OsdSynch.diff

Major changes are:

1. Semaphore is reimplemented with convar(9) instead of mutex(9).

2. Semaphore with ACPI_WAIT_FOREVER option actually waits forever now.

3. Obsolete and/or hidden debugging knobs and macros are removed.

4. ACPI-CA introduced AcpiOs*Mutex() to complement AcpiOs*Semaphore():

	http://bugzilla.kernel.org/show_bug.cgi?id=6634

   These functions are implemented and turned on by default.

5. Spinlock is reimplemented with sx lock and more closely implements 
the intended behaviour (e.g., save/restore interrupts).

It is orthogonal to Nate's effort of rewriting acpi_ec.c but I'd like 
get more feedback *with* his last patch (revision D) because his 
patch will be committed sooner or later. ;-)

Please test/review and let us know if there is any regression or not.

Thanks!

Jung-uk Kim