Add line returns

Add line returns to the help message so that the terminal won't end up on the same line.
Add optional startFilePos and endFilePos attributes

The lexer can now optionally add startFilePos and endFilePos
attributes, which are offsets in to the lexed code string.

The end offset currently points one past the last character of
the token - this is pending further discussion.

The attributes are not added by default and have to be enabled
using the new 'usedAttributes' lexer option:

	$lexer = new Lexer([
		'usedAttributes' => [
			'comments', 'startLine', 'endLine',
			'startFilePos', 'endFilePos'
		]
	]);
Support file offsets in emulative lexer as well

Also run normal lexer tests against emulative lexer and fix a bug
in __halt_compiler() handling found as a result.
Add missing require in tests

Test files aren't autoloaded, so this was order-dependent.
Merge pull request #152 from Fullmetal5/master

Add line returns in php-parse help message
Merge https://github.com/nikic/PHP-Parser
resync with nikic master branch