Update brew.plugin.zsh

Add `brew cleanup` command to `bubu` alias
Merge pull request #2969 from nicolas-brousse/patch-1

Update brew.plugin.zsh
Brings all directory stuff to directories.zsh

- Cleans out aliases.zsh.
- Removes unneeded cd function.
Changed upgrade remote to 'upstream'
Pushes autoenv code to its plugin.

Sources the activate.sh file or informs the user, that its not
available.
Overriding the cd function, as it was formerly done, is not needed
anymore, activate.sh does this by itself.
Show literal command in title instead of unaliased
Refactors history alias and moves it.

More compact case statement instead of the ugly if elif... else
statement. Moves it to history.zsh
Added doubleend theme from Nettuts+

This commits have been squashed:
- Added doubleend theme from Nettuts+
- Better git prompt on doubleend theme
- Syntax fixes, precmd inside $PROMPT to work with Ctrl+L
- Refactoring doubleend theme
- Cleanup, comments added
- Variables wrapped in double quotes in spacing()
- Modified $PROMPT to single line; cleanup.
- Modified CTRL+L behaviour to execute precmd() prompt line
- Renaming functions. Fixes git autocompletion
- Theme refactor. Works on CTRL+L and resizing
- Simplification of if-else
Moves remaining aliases to misc and deletes file.

There were only three aliases left in aliases.zsh
File deleted!
Add battery gauge custom plugin, dependency of doubleend theme.
Moves a bindkey call from misc to key-bindings.
Add return codes to agnoster theme

This adds the ability to show the return code of every process in a pipe chain,
as long as at least one of them returns a value other than 0.
There is the option to disable this behaviour as well.
Merged from robbyrussell/oh-my-zsh/pull/2573 (by @diogovk)
Deletes dot aliases from common-aliases.

They are implemented in lib anyway.
Fix a typo
Merge branch 'lfdm-cleaning_lib' into dev
Merge remote-tracking branches 'ncanceill/omz-bootstrap' and 'ncanceill/plugin-git' into dev