- Changing it for 4.0.2 so that we don't have backwards compatibility
- problems later on

Added PHP API for registering tick functions.  Ticks is a per-instruction
callback in Zend that allows us to implement cooperative multitasking
within PHP.  Example:

In extension code:

php_add_tick_function(my_tick_func);

void my_tick_func(int count) {
    php_printf("[tick %d]", count);
}

In PHP code:
<?php

declare(ticks = 1) {
    print "there should be two ticks here.\n";
}

?>

* Added copyright header to run-test.php