[Toybox] Shell corner cases.

[Rob Landley]

FYI, I'd prefer not to implement either of these in toybox:

1) function names with / in them

   $ which sudo
   /usr/bin/sudo
   $ /usr/bin/sudo() { echo owned; }
   $ /usr/bin/sudo
   owned
   $ ./sudo() { echo still owned; }
   $ ./sudo
   still owned

2) deferred alias definitions

   $ alias potato='echo hello'; potato
   bash: potato: command not found
   $ potato
   hello

Is there a strong reason for either one?

Rob