Make cmdstr be able to pull from and write to clipboard
Make cmdstr be able to pull from and write to clipboard

Now the common use-case is shortened from:

cb | cmdstr | cb

to:

cmdstr -c

Also added logging to stderr and changed the meaning of arguments
to indicate what the *source* is (defaulting to Python), so that
'cmdstr s' is mnemonic vs 'cmdstr -r' and not being able to remember
which direction is "reverse".

kbd/setup,kbd/setup,kbd/setup,kbd/setup,kbd/setup