PHP solution using the zero-width space

This uses a zero-width space (U+200B) to seem smart. It basically gets
as far as code that looks like this:

```
echo gg().​().​().​().​('al');
```

Or this:

```
echo g()->​()->​()->​()->​('al');
```

As other contributors have noted, PHP's lack of a uniform variable
syntax (https://wiki.php.net/rfc/uniform_variable_syntax) means that
doing this the correct way is impossible at the moment without some
really cool self-modifying hackery and `__HALT_COMPILER` nonsense. If
that RFC passes then this solution will work without the trickery.