Filter arguments passed to bin/wp proxy to allow spaces

**Issue**

Attempting to pass any argument or flag value with a space in it fails with the error `Too many positional arguments`. This is because bash's `$@`argument reference strips original quoting syntax.

**Use case**

Any of these will show the problem:
```
wp option add test123 "foo bar baz"
wp option add test123 'foo bar baz'
wp option add test123 foo\ bar\ baz

wp export --dir="/path with/some spaces/"
wp export --dir='/path with/some spaces/'
wp export --dir=/path\ with/some\ spaces/
```

This becomes increasingly critical for plugins like VIP Scanner, where required arguments contain spaces:

`wp vip-scanner scan-theme --theme="twentyfourteen" --scan_type="VIP Theme Review"`

**Solution**

Use awk to add quotes back to arguments that contain spaces, giving special treatment to --flag=value syntax.

**Test script**

`wp test-wp-filter escaped\ space --long_flag-name="foo bar" --single-quotes='foo bar' --escaped=foo\ bar --no-equals "foo bar" no quotes here  "Escaping \"double quotes\" is fine"`

Expected output:
```
'escaped space'
--long_flag-name='foo bar'
--single-quotes='foo bar'
--escaped='foo bar'
--no-equals
'foo bar'
no
quotes
here
'Escaping "double quotes" is fine'
```

**Test environment**

* VIP Quickstart d68e1a2
* WP-CLI `0.15.0`
* Mac OS `10.9.3`
Merge pull request #174 from pdclark/f/wp-cli-allow-spaces

Filter arguments passed to bin/wp proxy to allow spaces
Hide permalinks menu

Closes #168
Enable global terms

Closes #186
Fix failing twentyfourteen install

Instead of re-downloading and installing twentyfourteen, use the copy we
already check out via the wpcom-themes repo.

see #157
Merge pull request #190 from Automattic/bug/failing-twentyfourteen-install

Fix failing twentyfourteen install
Set pub/twentyfourteen as the default theme

Instead of activating pub/twentyfourteen every time
Puppet runs, we can just activate it for all new
sites in Quickstart. The previous method caused
twentyfourteen to always be active after a Puppet run.

Ping #190
Restart the VM when we init (on Windows)
Don't checkout plugins repo in vip-init.ps1

The plugins repo is public now. We can check this out with Puppet.
Disable automatic creation of intermediate images

On WordPress.com, we use Photon to generate image sizes on the fly.
Move wpcom things to wpcom.php and vip things to vip.php
Install the latest stable version of WP-CLI
Removing the pre-commit script to avoid confusion

See #204
Removing the pre-commit script to avoid confusion

See #204
Add support for VMWare Fusion and update to 13.10
Try the older box
Don't need to specify provider here
Ignore upgrade directory
Ignore WP-CLI when in development mode
Merge pull request #207 from danielbachhuber/ignore-wp-cli

Ignore WP-CLI when in development mode