mg: add new package/microscopic emacs style editor

For Emacsian!

You can use "Dired", which is Emacsian's favorite.
You can also use "re-search".

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>

utils/mg/patches/900-musl_compatibility.patch

@@ -0,0 +1,13 @@
+--- a/fileio.c
++++ b/fileio.c
+@@ -23,6 +23,10 @@
+ #include <string.h>
+ #include <unistd.h>
+ 
++#ifndef DEFFILEMODE
++#define DEFFILEMODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)
++#endif
++
+ #include "def.h"
+ #include "kbd.h"
+ #include "pathnames.h"