Fix for OS X build under x-windows.  Separated out sound option.
Added new etherlave network option for OS X.
Added file-level comments.
Darwin/lowmem and Darwin/pagezero do not need to be removed for clean.
Updated coding style.
More coding style updates.
Remove 15 bit video for OS X.  This mode doesn't seem to work.

This also fixes 2-bit, 4-bit, and 8-bit modes.
Removed clean rule for etherslavetool.
Added clean rule for etherslavetool.
Fixed code that removed 15-bit color mode.

15-bit color mode is now removed on all platforms.
The removal of 15-bit color mode now happens before the sort.
Updated a variable name.
Changed list length calculation to use C++'s clever pointer
subtraction.
Merge branch 'buildfix'
Merge branch 'osx-video-fix'
Merge branch 'etherslave'

Conflicts:
	BasiliskII/src/Unix/configure.ac