STYLE: remove unnecessary stdout, stderr /dev/null redirects

- no stderr redirect needed:
    * 'command -v'

- no stdout/stderr redirect needed:
    * 'rm -f'

STYLE: consistent spacing after redirects

tutorials/IO/dictionary/Allclean

@@ -1,6 +1,7 @@
 #!/bin/sh
 cd ${0%/*} || exit 1                        # Run from this directory
+#------------------------------------------------------------------------------
 
-rm log.* 2>/dev/null                        # No application, clean manually
+rm -f log.*                                 # No application, clean manually
 
 #------------------------------------------------------------------------------