patch 8.0.0716: not easy to start Vim cleanly

Problem:    Not easy to start Vim cleanly without changing the viminfo file.
            Not possible to know whether the -i command line flag was used.
Solution:   Add the --clean command line argument.  Add the 'viminfofile'
            option.  Add "-u DEFAULTS".
diff --git a/runtime/doc/usr_01.txt b/runtime/doc/usr_01.txt
index c45c156..b450c4e 100644
--- a/runtime/doc/usr_01.txt
+++ b/runtime/doc/usr_01.txt
@@ -1,4 +1,4 @@
-*usr_01.txt*	For Vim version 8.0.  Last change: 2010 Nov 03
+*usr_01.txt*	For Vim version 8.0.  Last change: 2017 Jul 15
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -140,19 +140,19 @@
 
 1. Copy the tutor file.  You can do this with Vim (it knows where to find it):
 >
-	vim -u NONE -c 'e $VIMRUNTIME/tutor/tutor' -c 'w! TUTORCOPY' -c 'q'
+	vim --clean -c 'e $VIMRUNTIME/tutor/tutor' -c 'w! TUTORCOPY' -c 'q'
 <
    This will write the file "TUTORCOPY" in the current directory.  To use a
 translated version of the tutor, append the two-letter language code to the
 filename.  For French:
 >
-	vim -u NONE -c 'e $VIMRUNTIME/tutor/tutor.fr' -c 'w! TUTORCOPY' -c 'q'
+	vim --clean -c 'e $VIMRUNTIME/tutor/tutor.fr' -c 'w! TUTORCOPY' -c 'q'
 <
 2. Edit the copied file with Vim:
 >
-	vim -u NONE -c "set nocp" TUTORCOPY
+	vim --clean TUTORCOPY
 <
-   The extra arguments make sure Vim is started in a good mood.
+   The --clean argument makes sure Vim is started with nice defaults.
 
 3. Delete the copied file when you are finished with it:
 >