Match all functionality.

Added the ability to optionally return the results of **all** matching cases, instead of just the first matching case, by adding a `match="all"` parameter. This allows for amazing flexibility without having to create several different tags.

Example:
```
{exp:switchee variable="{page_type}" match="all" parse="inward"}
	{case value="section_landing|section_sub_page"}
		<p>This will show for landing and sub pages.</p>
	{/case}

	{case value="section_landing"}
		<p>This will also show if we're on landing pages.</p>
	{/case}

	{case value="section_sub_page"}
		<p>This will also show if we're on sub pages.</p>
	{/case}

	{case default="yes"}
		<p>This will still work as expected if no case is matched.</p>
	{/case}
{/exp:switchee}
````