Find and exec vvv-init.sh before finding vvv-nginx.conf

The vvv-init.sh script may in fact generate vvv-nginx.conf files on the fly.
Inline auto-site-setup so init-generated vvv-hosts can be found
Accomodate server directives that have hundred(s) of server_names

For example large multisite networks.

This change enables a network with 179 server_names.
Increase auto-site-setup seach depth from 4 to 5
Merge pull request #199 from x-team/init-then-nginx-conf

Allow vvv-init.sh to generate vvv-hosts and vvv-nginx.conf, etc
Make sure .subversion directory exists before copying user config
Add Ruby and Sass
Merge pull request #205 from aaronjorbin/ruby

Add Ruby and Sass to meet new WordPress develop.svn requirements

Closes #204
Include note in readme about Virtualbox version on Mavericks
Modifications to language around the use of Virtualbox 4.3.2 with OS X MAvericks
Update contributors list
capital_B_dangit() - s/Virtualbox/VirtualBox/
Update the grunt module we install to match the updates core grunt scripts requirements.
Merge pull request #209 from westi/grunt-updates

Update the grunt module we install to match the updates core grunt scripts
Add !/bin/bash to first line of provisioning
Implement style guide recommendations for if/for/while statements

From the guide:

"Put ; do and ; then on the same line as the while, for or if.

Loops in shell are a bit different, but we follow the same principles as with braces when declaring functions. That is: ; then and ; do should be on the same line as the if/for/while. else should be on its own line and closing statements should be on their own line vertically aligned with the opening statement."

Thinking of `; then` or `; do` as an opening bracket–`{`–for the statement makes a lot of sense when trying to grasp this in the mind of a day to day PHP dev.
Implement $(command) instead of backticks

From the style guide:

"Nested backticks require escaping the inner ones with \. The $(command) format doesn't change when nested and is easier to read."

We have a couple places where commands are nested and this totally helps the confusion level there.
Implement [[...]] for testing if statements

From the style guide:

"[[ ... ]] reduces errors as no pathname expansion or word splitting takes place between [[ and ]] and [[ ... ]] allows for regular expression matching where [ ... ] does not."

Consistency makes sense more than anything here and we were already using [[...]] in more places than [...]. There were a few places where there were no brackets at all, those have been converted as well.
Implement proper test for non empty string

From the style guide:

"use tests for empty/non-empty strings or empty strings rather than filler characters"

In the one test for a non-empty string, use `-n` instead of `!= ""`
Correct a remaining backtick to $() issue