GitLab

This adds two new theme functions for git:
* `git_prompt_behind` works in a identical fashion to `git_prompt_ahead`
  and will output a format variable (`ZSH_THEME_GIT_PROMPT_BEHIND`) if
  the branch is behind.
* `git_prompt_remote` will output one format variable if the branch
  exists on remote (`ZSH_THEME_GIT_PROMPT_REMOTE_EXISTS`), and another
  if the branch is unpublished (`ZSH_THEME_GIT_PROMPT_REMOTE_MISSING`).

The old `git_prompt_ahead` has been changed. Using git log is subject
to formatting in .gitconfig, which can be overridden and will break
this function. Relying on rev-list is much more stable.

Do not put explicit dot in $cdpath, since it causes problems on Cygwin due to an underlying zsh bug.

The -h options in l, ll, and la were lost in 25b1cd68. There's no reason
to remove them.

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).

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.

There were only three aliases left in aliases.zsh
File deleted!

More compact case statement instead of the ugly if elif... else
statement. Moves it to history.zsh

- Cleans out aliases.zsh.
- Removes unneeded cd function.

contaminating script/function output

We are running oh-my-zsh on a shared install and the only issue is each
user having a custom cache dir. This will allow us to set the cache dir
to ZSH_CACHE_DIR=~/oh-my-zsh/cache/ .

I've seen stranger things on OS X, unfortunately.
This reverts commit 1f5cecee4768be192e439a72a873a6cfe8720927.

Revert PR #3359 as this is breaking stuff for many folks. Need to rethink how we handle system defaults differently on this

Commit 81004dfa reverted the change
in 9b811fb6 when editing the merge
conflict from #2928.

This commit fixes that so that we don't make the same mistake again.

First seen in http://git.io/Cdaj5Q

This avoid spawning additional processes, as the $USER variable will
**always** contain the current logged-in user.

From http://zsh.sourceforge.net/Doc/Release/Options.html#Completion-4

> AUTO_NAME_DIRS
> Any parameter that is set to the absolute name of a directory immediately
> becomes a name for that directory, that will be used by the ‘%~’ and
> related prompt sequences, and will be available when completion is performed
> on a word starting with ‘~’.
> (Otherwise, the parameter must be used in the form ‘~param’ first.)

Explained in more detail in
https://github.com/wayneeseguin/rvm/issues/3091#issuecomment-60083194

Related issues:
https://github.com/robbyrussell/oh-my-zsh/issues/2857
https://github.com/robbyrussell/oh-my-zsh/issues/3238
https://github.com/wayneeseguin/rvm/issues/3091

In older version of zsh, `add-zsh-hook` is not available, causing issues like:

```
/Users/hugo/.oh-my-zsh/lib/termsupport.zsh:32: add-zsh-hook: function definition file not found
/Users/hugo/.oh-my-zsh/lib/termsupport.zsh:33: add-zsh-hook: function definition file not found
```

See https://github.com/robbyrussell/oh-my-zsh/issues/748. This patch pulls in the changes suggested in https://github.com/robbyrussell/oh-my-zsh/issues/748#issuecomment-37862691 by @mcornella and I have tested it on RHEL 5.

Some environments (such as Android) does not have /usr/bin.