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.
Escape # to prevent it being recognized as a comment

#ignore
Improve indentNextLinePattern

Rather than try to match lines that should cause the next line to be indented we now rule out lines that should prevent it from being so. Fixes #38 and #32.
Add tests for indentation rules