patch 7.4.2111

Problem:    Defaults are very conservative.
Solution:   Move settings from vimrc_example.vim to defaults.vim.  Load
            defaults.vim if no .vimrc was found.

src/os_amiga.h

@@ -160,6 +160,9 @@ typedef long off_t;
 #ifndef USR_VIMRC_FILE4
 # define USR_VIMRC_FILE4 "$VIM/.vimrc"
 #endif
+#ifndef VIM_DEFAULTS_FILE
+# define VIM_DEFAULTS_FILE "$VIMRUNTIME/defaults.vim"
+#endif
 #ifndef EVIM_FILE
 # define EVIM_FILE	"$VIMRUNTIME/evim.vim"
 #endif