Solaris 10 includes setenv() (So don't use -DNEEDS_SETENV)

Should fix the setenv() errors when compiling on Solaris 10.

src/build/Common.gmake

@@ -227,6 +227,10 @@ endif
 # OS Specific Flags
 ifeq ($(os),sunos)    # Solaris
  CFLAGS	+= -D__solaris__ -DNEEDS_DAEMON -DNEEDS_FORKPTY -DNEEDS_SETENV -DNEEDS_CFMAKERAW
+ # Solaris 10 provides setenv()
+ ifeq ($(shell if [ `uname -r | sed 's/^..//'` -lt 10 ] ; then echo "Yes" ; else echo "No" ; fi),Yes)
+  CFLAGS += -DNEEDS_SETENV
+ endif
  LDFLAGS	+=	-L/opt/sfw/lib
 endif
 ifeq ($(os),netbsd)	# NetBSD