zsh/rc: display network namespace in prompt
zsh/rc: prepend "--" in X alias Prevents possible interpretation of options from X selection.
shell: replace valgrind wrapper with environment variable
zsh/rc: use current input for incremental searches
zsh/rc: don't abort if there are no autoloadable functions Broken since 02b16f5 ("zsh: functions: remove extract", 2018-07-17).
Move to shell/ in preparation for merge into new dotfiles repository