Closes #6048

Closes #10034

Antigen doesn't call `compinit` until the user prompt is about to be shown,
which means `_cache_invalid` isn't automatically autoloaded. This patch
fixes that, though we should work towards a better caching mechanism.

Fixes #9490

Fixes #9236

Added `co` alias for `composer outdated` and `cod` for `composer
outdated --direct`

Closes #5127

Fixes #6647
Closes #6664

- fasd
- history
- mercurial
- pylint
- repo
- yii2

* Fix for Composer's bin when Composer isn't global

When Composer isn't globally installed, the `composer global` call results in an error. This checks to see if Composer is available before making the call. When Composer isn't available, it will just manually set the directories.

* Fix Composer brackets in global bin directory

* composer: Apply feedback from ricpelo

This applies ricpelo's feedback at https://github.com/robbyrussell/oh-my-zsh/pull/6240#pullrequestreview-64253321

* composer: Fix path check syntax

* composer: test with $commands[] syntax

Add the proper config bin directory to `PATH` instead of the previously (incorrect) fixed `~/.composer/vendor/bin`. Nowadays the right config dir is `~/.config/composer/vendor/bin`.

Adds remove/global remove and optimize-autoloader commands.

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

This plugin currently doesn't autocomplete composer commands if there is no composer.json in the current dir. However, the commands create-project, init, search, selfupdate and show are still useful without a composer.json!