add information on zsh completion setup for better foolproofing
fix platform detection bug for non-Cygwin Windows
fix obvious bug in Run timeout

likely still doesn't work but also isn't being actively used yet
remove dead code
reorganize fake_exists a bit in test_config
add some tests to improve coverage
tidy up functional tests some
simplify shell_config internals
let get_ve_base pass through absent paths for error message generation
version bump