additional tmux aliases
Fix chruby plugin to not complain if chruby is *not* installed
Throw an error message when $WORKON_HOME is not set

Took me a while to figure this one out, and I have a default installation of virtualenvwrapper -- this is a soft fix, just put an error message. But perhaps the fix should be to use the default value `~/.virtualenvs`.
Fixed output issues webith websearch plugin.

- if user has rm set as an alias to 'rm -i' user is prompted to whether to
  remove the nohup.out file.

 $ ddg fools
	nohup: ignoring input and appending output to ‘nohup.out’
	rm: remove regular empty file ‘nohup.out’?

- if output redirected to a file nohup will not create nohup.out and rm is
  unecessary.
Added Yii2 command completion
Add yii2 readme
mira theme shows active node, ruby and java versions
added node- before node version for consistency
Updated Yii2 command completion
Merge pull request #3397 from peteches/master

Fixed output issues webith websearch plugin.
Merge pull request #3352 from benjaoming/virtualenvwrapper_workon_unset

Throw an error message when $WORKON_HOME is not set
Merge pull request #3338 from eripa/chruby_fix

Fix chruby plugin to not complain if chruby is *not* installed
Merge pull request #3146 from typekpb/tmux-aliases

additional tmux aliases
Merge pull request #3404 from ekaragodin/master

Added Yii2 command completion
Merge pull request #3407 from rawberg/mira-theme

mira theme shows active node, ruby and java versions
Clean up and fix +1/-0 syntax to work as expected

This change follows this proposed behaviour:

 Ctrl+Shift+Left:  move to last visited directory
 Ctrl+Shift+Right: move to next visited directory

an alternative behaviour would be:

 Ctrl+Shift+Left:  move directory to the left in `dirs` output
 Ctrl+Shift+Right: move directory to the right in `dirs` output

It also introduces `setopt nopushdminus` as a way to standardise
pushd syntax. It's value wasn't clear before, which has been the
cause of so many pull requests regarding this plugin not working
in some environments.
Run pushd command directly and trigger prompt redraw
Emulate zsh in zlewidgets instead of static setopt command

This way the user can keep their preferred pushd syntax while enabling
us to use a standard syntax in our defined functions.

To explain further, without a clear value on the PUSHD_MINUS option, we
could be changing the +1/-0 values all we want, that some user would
find that it didn't work for him.

We have two options, then:
- Setting a particular value, which was my first approach.
- Using `emulate -L zsh` to ensure all options defined in the function's
  body won't be passed along to the main zsh instance.
  For more info see:
  http://zsh.sourceforge.net/Doc/Release/Shell-Builtin-Commands.html#index-emulate