Description:
------------
The function keyword is pretty deprecated in php atm. If you got a function inside 
a class people always refer to it as a 'method' and not a function. Besides that, 
there is actually no need for that keyword... 
class foo {
  public function foobar() {}
}
Is actually the same as:

class foo {
  public foobar() {}
}

Should not be hard to understand that it's a function or method...

I propose to either change the keyword to method or remove it completely

Test script:
---------------
<?php
class foo {
  // old
  public function foobar() {}

  // suggestion 0
  public method foobar() {}

  // suggestion 1
  public foobar() {}
}