Allow closing multiple functions to decrease indent level

Fixes #33.
Support for nested arrays in indentation rules

For instance:

```
<?php
$array = array(
    "foo" => "bar",
    42    => 24,
    "multi" => array(
         "dimensional" => array(
             "array" => "foo"
         )
    )
);
```
Improve support for nowdocs

Nowdocs can now contain syntax highlighting for supported languages, fixes #31.

Also add support for double-quoted identifiers in regular heredocs.
Don't indent after a # comment line

This mirrors the same indentNextLinePattern setting for `//` commented lines.
Expand where PHP tags are allowed

PHP tags are now injected between script tags as well as inside a tag where previously they were only allowed inside of quoted attributes. Fixes #35 and #37.
Open documentation in web browser.
Use curly brace syntax for control structures in PHP tags.