* ssh-agent: lock this script with a mkdir style mutex

This script is a kind of singleton pattern and is not reentrant.
If several shells are oppened in a fast sequence, then several
independent ssh-agents would be created, which is not acceptable.
A mutex is required.
Signed-off-by: NNuno Goncalves <nunojpg@gmail.com>

* ssh-agent: only start agent if .ssh dir exists

To use the same profile system-wide, it might happen
that the .ssh directory does not exist
(typically $HOME/.ssh/). This would trigger a error.

Creating the directory would be a option, but it
usually will not make sense to do so because it means
the user doesn't have ssh keys or config.
Signed-off-by: NNuno Goncalves <nunojpg@gmail.com>

* ssh-agent: adds lazy option to disable key loading on start

Option is documented on updated README.md
Signed-off-by: NNuno Goncalves <nunojpg@gmail.com>

* ssh-agent: simplify agent-forwarding checking
Signed-off-by: NNuno Goncalves <nunojpg@gmail.com>
Co-authored-by: NRobby Russell <robby@planetargon.com>

Co-authored-by: NCorey Hinkle <corey.hinkle@five9.com>

This commit fixes an issue where the prompt symbol is white when vcs_info is displayed in the gentoo theme.

By default, cargo provides alias for some commonly used functions. This patch
makes it that those alias will complete the same as their full commands.

Default alias:
b -> build
c -> check
t -> test
r -> run

Since cargo allows users to define custom alias it would be nice if
oh-my-zsh automatically detected those and preformed completions as such
but that would be a much more complex patch.

`pk-command-not-found` doesn't accept `--` as an argument. This is what happens when `--` is the first argument:

```
$  gem
zsh: --: command not found...
```

Co-authored-by: NKapil Pau <kapilpau@hotmail.com>
Co-authored-by: NCallMeLaNN <CallMeLaNN@users.noreply.github.com>

As documented in the README, `npm i -f` forces npm to install the specified packages from a remote
package registry, even if local copies exist on disk caches.

On large mercurial projects, using `hg status` to show dirty prompt
causes significant delay.

This commit checks a local hg config value of `oh-my-zsh.hide-dirty` to
skip dirty check.

Users who wish to skip dirty check can add this to their `.hg/hgrc`
file.

```
[oh-my-zsh]
hide-dirty = 1
```

This config value uses the same naming as ones found for git, in file
lib/git.zsh.

This commit fixes an issue in the gentoo theme introduced in 3bb5e977.
Due to incorrect line width calculations, colors are incorrectly applied
when using tab.

Fixes #9778
Signed-off-by: NThomas De Backer <mosterdt@debacker.me>

BREAKING CHANGE: the various update aliases will no longer run `abs` and `aur`, which are either
deprecated or nonexistent. See https://archlinux.org/news/deprecation-of-abs/ for more.

Co-authored-by: NMarc Cornellà <hello@mcornella.com>

Fixes #8427

Without this patch, if the called zle widgets have been redefined this plugin might come into
conflict. Related: #9770.