patch 8.0.1197: MS-Windows build instructions are not up to date

Problem:    MS-Windows build instructions are not up to date.
Solution:   Adjust the instructions.  Fix the nsis script.

Makefile

@@ -131,6 +131,7 @@ MINOR = 0
 # - > make dossrc
 #   > make dosrt
 #   Unpack dist/vim##rt.zip and dist/vim##src.zip on an MS-Windows PC.
+#   This creates the directory vim/vim80 and puts all files in there.
 # Win32 console version build:
 # - See src/INSTALLpc.txt for installing the compiler and SDK.
 # - Set environment for Visual C++ 2015:
@@ -186,8 +187,9 @@ MINOR = 0
 #	gvimext64.dll in src/GvimExt
 #	VisVim.dll in src/VisVim
 #   Note: VisVim needs to be build with MSVC 5, newer versions don't work.
-#   gvimext64.dll can be obtained from http://code.google.com/p/vim-win3264/
-#	It is part of vim72.zip as vim72/gvimext.dll.
+#   gvimext64.dll can be obtained from:
+#   https://github.com/vim/vim-win32-installer/releases
+#	It is part of gvim_8.0.*_x64.zip as vim/vim80/GvimExt/gvimext64.dll.
 # - Make sure there is a diff.exe two levels up (get it from a previous Vim
 #   version).  Also put winpty32.dll and winpty-agent.exe there.
 # - go to ../nsis and do:

nsis/gvim.nsi

@@ -351,7 +351,7 @@ Section "Add an Edit-with-Vim context menu entry"
 	  # Can't copy gvimext.dll, create it under another name and rename it
 	  # on next reboot.
 	  GetTempFileName $3 $0\GvimExt64
-	  File /oname=$3 ${VIMSRC}\GvimExt64\gvimext.dll
+	  File /oname=$3 ${VIMSRC}\GvimExt\gvimext64.dll
 	  Rename /REBOOTOK $3 $0\GvimExt64\gvimext.dll
 !ifdef HAVE_NLS
 	  GetTempFileName $3 $0\GvimExt64

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1197,
 /**/
     1196,
 /**/