Port to 12 other Platforms.

This patch adds support to compile and run git on 12 additional platforms.
The platforms are based on UNIX Systems Labs (USL)/Novell/SYS V code base.
The most common are Novell UnixWare 2.X.X, SCO UnixWare 7.X.X,
OpenServer 5.0.X, OpenServer 6.0.X, and SCO pre OSR 5 platforms.

Looking at the the various platform headers, I find:

	#if defined(_KERNEL) || !defined(_POSIX_SOURCE) \
	     && !defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)

which hides u_short and other typedefs that other header files on these
platforms depend on.  WIth _XOPEN_SOURCE defined, sources that include
system header files that depend on the typedefs such as u_short cannot be
compiled on these platforms.

__USLC__ indicates UNIX System Labs Corperation (USLC), or a Novell-derived
compiler and/or some SysV based OS's.

__M_UNIX indicates XENIX/SCO UNIX/OpenServer 5.0.7 and prior releases
of the SCO OS's.  It is used just like Apple and BSD, both of these
shouldn't have _XOPEN_SOURCE defined.

This is with suggestions and modifications from

Daniel Barkalow, Junio C Hamano, Thomas Harning, and Jeremy Maitin-Shepard.
Signed-off-by: NBoyd Lynn Gerber <gerberb@zenez.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Makefile

@@ -564,6 +564,45 @@ endif
 ifeq ($(uname_S),GNU/kFreeBSD)
 	NO_STRLCPY = YesPlease
 endif
+ifeq ($(uname_S),UnixWare)
+	CC = cc
+	NEEDS_SOCKET = YesPlease
+	NEEDS_NSL = YesPlease
+	NEEDS_SSL_WITH_CRYPTO = YesPlease
+	NEEDS_LIBICONV = YesPlease
+	SHELL_PATH = /usr/local/bin/bash
+	NO_IPV6 = YesPlease
+	NO_HSTRERROR = YesPlease
+	BASIC_CFLAGS += -Kthread
+	BASIC_CFLAGS += -I/usr/local/include
+	BASIC_LDFLAGS += -L/usr/local/lib
+	INSTALL = ginstall
+	TAR = gtar
+	NO_STRCASESTR = YesPlease
+	NO_MEMMEM = YesPlease
+endif
+ifeq ($(uname_S),SCO_SV)
+	ifeq ($(uname_R),3.2)
+		CFLAGS = -O2
+	endif
+	ifeq ($(uname_R),5)
+		CC = cc
+		BASIC_CFLAGS += -Kthread
+	endif
+	NEEDS_SOCKET = YesPlease
+	NEEDS_NSL = YesPlease
+	NEEDS_SSL_WITH_CRYPTO = YesPlease
+	NEEDS_LIBICONV = YesPlease
+	SHELL_PATH = /usr/bin/bash
+	NO_IPV6 = YesPlease
+	NO_HSTRERROR = YesPlease
+	BASIC_CFLAGS += -I/usr/local/include
+	BASIC_LDFLAGS += -L/usr/local/lib
+	NO_STRCASESTR = YesPlease
+	NO_MEMMEM = YesPlease
+	INSTALL = ginstall
+	TAR = gtar
+endif
 ifeq ($(uname_S),Darwin)
 	NEEDS_SSL_WITH_CRYPTO = YesPlease
 	NEEDS_LIBICONV = YesPlease

git-compat-util.h

@@ -39,7 +39,7 @@
 /* Approximation of the length of the decimal representation of this type. */
 #define decimal_length(x)	((int)(sizeof(x) * 2.56 + 0.5) + 1)
 
-#if !defined(__APPLE__) && !defined(__FreeBSD__)
+#if !defined(__APPLE__) && !defined(__FreeBSD__)  && !defined(__USLC__) && !defined(_M_UNIX)
 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 #endif