Delete the old 'macosx' directory completely.

The current state of the OS X GTK port is looking more or less
plausible - it's not finished, of course, but then neither was the old
native Cocoa port. So I'm inclined to advertise it as *the* unfinished
OS X port: it's the one I intend to keep working on, and it's the one
I'd prefer people offered us help with if they're going to offer.

Hence, leaving the old macosx directory around is just confusing; that
directory is long-unmaintained, probably doesn't even compile, and its
only effect will be to mislead people into thinking it's still
relevant. I'm unilaterally deleting it; of course we can always
recover it from source control history if it's ever necessary to do
so.

Recipe

@@ -20,7 +20,6 @@
 !makefile gtk unix/Makefile.gtk
 !makefile unix unix/Makefile.ux
 !makefile am Makefile.am
-!makefile osx macosx/Makefile
 !makefile devcppproj windows/DEVCPP
 !makefile vstudio10 windows/VS2010
 !makefile vstudio12 windows/VS2012
@@ -28,7 +27,6 @@
 !srcdir charset/
 !srcdir windows/
 !srcdir unix/
-!srcdir macosx/
 
 # Help text added to the top of each Makefile, with /D converted
 # into -D as appropriate for the particular Makefile.
@@ -173,9 +171,6 @@ install:
 install-strip:
 	$(MAKE) install INSTALL_PROGRAM="$(INSTALL_PROGRAM) -s"
 !end
-!begin osx vars
-CFLAGS += -DMACOSX
-!end
 
 # List the man pages for the automake makefile.
 !begin am
@@ -231,7 +226,6 @@ GUITERM  = TERMINAL window windlg winctrls sizetip winucs winprint
 UXTERM   = TERMINAL uxcfg sercfg uxucs uxprint timing callback miscucs
 GTKTERM  = UXTERM gtkwin gtkcfg gtkdlg gtkfont gtkcols gtkmisc xkeysym
 	 + x11misc gtkcomm
-OSXTERM  = UXTERM osxwin osxdlg osxctrls
 
 # Non-SSH back ends (putty, puttytel, plink).
 NONSSH   = telnet raw rlogin ldisc pinger
@@ -254,7 +248,6 @@ MISC     = timing callback misc version settings tree234 proxy conf be_misc
 WINMISC  = MISC winstore winnet winhandl cmdline windefs winmisc winproxy
          + wintime winhsock errsock winsecur
 UXMISC   = MISC uxstore uxsel uxnet uxpeer cmdline uxmisc uxproxy time
-OSXMISC  = MISC uxstore uxsel osxsel uxnet uxpeer uxmisc uxproxy time
 
 # import.c and dependencies, for PuTTYgen-like utilities that have to
 # load foreign key files.
@@ -331,9 +324,6 @@ pageant  : [X] uxpgnt uxagentc pageant sshrsa sshpubk sshdes sshbn sshmd5
 	 + conf uxsignal nocproxy nogss be_none x11fwd ux_x11 uxcons gtkask
 	 + gtkmisc UXMISC
 
-PuTTY    : [MX] osxmain OSXTERM OSXMISC CHARSET U_BE_ALL NONSSH UXSSH
-         + ux_x11 uxpty uxsignal testback putty.icns info.plist
-
 ptermapp : [XT] GTKTERM uxmisc misc ldisc settings uxpty uxsel BE_NONE uxstore
          + uxsignal CHARSET cmdline uxpterm version time xpmpterm xpmptcfg
          + nogss gtkapp