Update runtime files.
updated for version 7.4.426
Problem:    README File missing from list of files.
Solution:   Update the list of files.
Added tag v7-4-426 for changeset 7ab9a9cf2859
updated for version 7.4.427
Problem:    When an InsertCharPre autocommand executes system() typeahead may
	    be echoed and messes up the display. (Jacob Niehus)
Solution:   Do not set cooked mode when invoked from ":silent".
Added tag v7-4-427 for changeset fca35aa9380a