Darwin build fails on xconsole.c

[Torrey Lyons]

Since the patch of July 7 by sandmann xconsole.c fails to build on Darwin with 
the error:

xconsole.c: In function 'get_pty':
xconsole.c:863: error: 'PTYCHAR1' undeclared (first use in this function)
xconsole.c:863: error: (Each undeclared identifier is reported only once
xconsole.c:863: error: for each function it appears in.)
xconsole.c:867: error: 'PTYCHAR2' undeclared (first use in this function)

These are defined in "../xterm/ptyx.h", which was dropped as an include in the 
recent patch. I suppose this might have been done for the modularization work. 
How should we fix this? Copying the definitions for PTYCHAR1 and PTYCHAR2 from 
ptyx.h will work, but this may not be the best solution.

--Torrey