tcsh: fix unmute

Remove the delay before our prompt reappears
tcsh: fix the help case (default) of the angel controller
tcsh/shell code: remove one level of 'eval' indirection

Remove the eval indirection to build multilines aliases.
Looks like I've invented (reinvented?) a different method than what I
had found in various docs about csh quirks (CshTop10, Csh programming
considered harmful).
Known method: alias cmd 'eval "..."'
My method: set xxx = '...'; alias cmd $xxx:q; unset xxx
This method allows to use the `"' inside the alias definition.
tcsh: change the temp script extension to .tcsh