Require POSIX.1 (1990) compliance on unix

Assume unix platforms support the original POSIX.1 standard.
Specifically, assume that if G_OS_UNIX, then we have chown(),
getcwd(), getgrgid(), getpwuid(), link(), <grp.h>, <pwd.h>,
<sys/types.h>, <sys/uio.h>, <sys/wait.h>, and <unistd.h>.

Additionally, since all versions of Windows that we care about also
have <sys/types.h>, we can remove HAVE_SYS_TYPES_H checks everywhere.

Also remove one include of <sys/times.h>, and the corresponding
configure check, since the include is not currently needed (and may
always have just been a typo for <sys/time.h>).

https://bugzilla.gnome.org/show_bug.cgi?id=710519

gio/gfile.c

@@ -41,9 +41,6 @@
 
 #include <string.h>
 #include <sys/types.h>
-#ifdef HAVE_PWD_H
-#include <pwd.h>
-#endif
 
 #include "gfile.h"
 #include "glib/gstdio.h"

gio/glocalfile.c

@@ -143,7 +143,7 @@ g_local_file_class_init (GLocalFileClass *klass)
 				  G_FILE_ATTRIBUTE_INFO_COPY_WITH_FILE |
 				  G_FILE_ATTRIBUTE_INFO_COPY_WHEN_MOVED);
   
-#ifdef HAVE_CHOWN
+#ifdef G_OS_UNIX
   g_file_attribute_info_list_add (list,
 				  G_FILE_ATTRIBUTE_UNIX_UID,
 				  G_FILE_ATTRIBUTE_TYPE_UINT32,

gio/glocalfileinfo.c

@@ -24,6 +24,8 @@
 
 #include "config.h"
 
+#include <glib.h>
+
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
@@ -35,10 +37,8 @@
 #endif
 #include <fcntl.h>
 #include <errno.h>
-#ifdef HAVE_GRP_H
+#ifdef G_OS_UNIX
 #include <grp.h>
-#endif
-#ifdef HAVE_PWD_H
 #include <pwd.h>
 #endif
 #ifdef HAVE_SELINUX
@@ -2158,7 +2158,7 @@ set_unix_mode (char                       *filename,
   return TRUE;
 }
 
-#ifdef HAVE_CHOWN
+#ifdef G_OS_UNIX
 static gboolean
 set_unix_uid_gid (char                       *filename,
 		  const GFileAttributeValue  *uid_value,
@@ -2442,7 +2442,7 @@ _g_local_file_info_set_attribute (char                 *filename,
   if (strcmp (attribute, G_FILE_ATTRIBUTE_UNIX_MODE) == 0)
     return set_unix_mode (filename, flags, &value, error);
   
-#ifdef HAVE_CHOWN
+#ifdef G_OS_UNIX
   else if (strcmp (attribute, G_FILE_ATTRIBUTE_UNIX_UID) == 0)
     return set_unix_uid_gid (filename, &value, NULL, flags, error);
   else if (strcmp (attribute, G_FILE_ATTRIBUTE_UNIX_GID) == 0)
@@ -2519,13 +2519,11 @@ _g_local_file_info_set_attributes  (char                 *filename,
 				    GError              **error)
 {
   GFileAttributeValue *value;
-#ifdef HAVE_CHOWN
+#ifdef G_OS_UNIX
   GFileAttributeValue *uid, *gid;
-#endif
 #ifdef HAVE_UTIMES
   GFileAttributeValue *mtime, *mtime_usec, *atime, *atime_usec;
 #endif
-#if defined (HAVE_CHOWN) || defined (HAVE_UTIMES)
   GFileAttributeStatus status;
 #endif
   gboolean res;
@@ -2555,7 +2553,7 @@ _g_local_file_info_set_attributes  (char                 *filename,
     }
 #endif
 
-#ifdef HAVE_CHOWN
+#ifdef G_OS_UNIX
   /* Group uid and gid setting into one call
    * Change ownership before permissions, since ownership changes can
      change permissions (e.g. setuid)

gio/glocalfileinfo.h

@@ -26,9 +26,7 @@
 #include <gio/gfileinfo.h>
 #include <gio/gfile.h>
 #include <sys/stat.h>
-#ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
-#endif
 
 G_BEGIN_DECLS
 

gio/glocalfileoutputstream.c

@@ -265,7 +265,7 @@ _g_local_file_output_stream_really_close (GLocalFileOutputStream *file,
 	  if (g_cancellable_set_error_if_cancelled (cancellable, error))
 	    goto err_out;
 	  
-#ifdef HAVE_LINK
+#ifdef G_OS_UNIX
 	  /* create original -> backup link, the original is then renamed over */
 	  if (g_unlink (file->priv->backup_filename) != 0 &&
 	      errno != ENOENT)

gio/glocalvfs.c

@@ -28,7 +28,7 @@
 #include "gvfs.h"
 #include <gio/gdummyfile.h>
 #include <sys/types.h>
-#ifdef HAVE_PWD_H
+#ifdef G_OS_UNIX
 #include <pwd.h>
 #endif
 #include <string.h>
@@ -155,7 +155,7 @@ g_local_vfs_parse_name (GVfs       *vfs,
 	    user_prefix = g_strdup (g_get_home_dir ());
 	  else
 	    {
-#ifdef HAVE_PWD_H
+#ifdef G_OS_UNIX
               struct passwd *passwd_file_entry;
               char *user_name;
 

gio/gsocket.c

@@ -48,7 +48,7 @@
 # include <sys/filio.h>
 #endif
 
-#ifdef HAVE_SYS_UIO_H
+#ifdef G_OS_UNIX
 #include <sys/uio.h>
 #endif