"throws" in function/method synopsis, like return 

Currently:
```
public string Qux::foo( string $baz , string $bar )
```
Should be (kinda):
```
public function /* Qux:: */ foo(string $baz , string $bar) : string, throws WhateverException;
```
It's often hard to figure out (or it's even not specified) that methods throw.
Exceptions aren't less important than return, so they must be documented just as well.