patch 8.1.0363: internal diff isn't used by default as advertised
Problem: Internal diff isn't used by default as advertised.
Solution: Add "internal" to the default value of 'diffopt'.
Also add couple of files missing from the distribution.
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 16aa422..a02618a 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -2615,7 +2615,7 @@
security reasons.
*'dip'* *'diffopt'*
-'diffopt' 'dip' string (default "filler")
+'diffopt' 'dip' string (default "internal,filler")
global
{not in Vi}
{not available when compiled without the |+diff|