added mkdir/rm
clean up
Revert "clean up"

This reverts commit 47e8197a458e68c77daf1bb4ec14934ee601a04e.
clean up
moved outp redir op handling to line_to_args
fixed docstring of line_to_args()
Fix terminal window size detection.

It now works properly when you have a repl_uart (assuming that
the repl-source stuff lands). I made it auto-detect if repl-source
is present.
Merge branch 'dev' of https://github.com/turbinenreiter/upy-shell into dev