Bump version

Overview of changes:

 *  Added extra shorthand arguments for common usage errors

    Things like missing positional arguments or unknown arguments need
    to be dealt with so often it warrants these shorthands.

 *  Fortified command, file and pipe delimiters

    Often it's helpful to see more clearly where output begins and where
    it ends.  Note that this is a small step from pretty.sh's total
    minimalism, on the other hand these file and command printers are
    not exactly minimalistic already; they are not intended for normal
    use but rather for debugging.

mkit.ini

 [project]
-    version     = 0.10.20
+    version     = 0.10.21
     codename    = FloatingPointError
     name        = Shellfu
     tagline     = Shell dot on steroids