Extract CWD notifier back out of auto-title hooks

Repost #3426: move DISABLE_AUTO_TITLE check to hooks

Repost #2819: fix virtualenvwrapper for Ubuntu and Debian

Fix Unicode problems by only setting LC_CTYPE if not set

LANG is a colon-separated list of prefered locales; LC_CTYPE is single entry,
therefore we need to remove all but one entry.

Also, there is no need setting it if it is already set (LC_ALL also sets
LC_CTYPE, so we check it too).

Ubuntu and Debian store the system-installed virtualenvwrapper in
/etc/bash_completion.d/virtualenvwrapper, so that it gets automatically sourced
at startup in Bash. By not putting it somewhere in $PATH, they end up excluding
others (e.g. Zsh) that might want to use that file. Oops!

The virtualenvwrapper plugin should account for this so that Ubuntu (or Debian)
users don't end up with this message:

zsh virtualenvwrapper plugin: Cannot find virtualenvwrapper.sh. Please install with `pip install virtualenvwrapper`.

even when they have a virtualenvwrapper installed to a known location.

[Plugin composer] Multiple fixes

Refactor and improve web-search plugin

Repost #2606: fix git status in rkj-repos theme

Add Fedora support for command-not-found plugin

Save ZSH path in newly created .zshrc

remove path not found for linuxonly theme

Removing 'local' usage to prevent issue when installed with antigen

Added trapwinch to vi-mode plugin.

dircycle plugin: clean and fix logic once and for all

sudo: maintain cursor position

Repost #2422: cleaning lib

Move the DISABLE_AUTO_TITLE check from title() to the preX hook
functions that call it, to allow the title() function to be used
directly by user or other callers.

This is because we can't be sure which arguments require a json file
and which don't, so the `else' statement will always be difficult to
check for correctness.

Use $_comp_command1 for command list generation instead of 'composer':

  `$_comp_command1` contains the command written in the command line.
  This allows us to have a different composer name