Speed up

Using this code as example:

```php
<?php
 
for ($i=0; $i<100000; $i++) {
    $output = $i*$i;
    #print "Hello world " . ($output) . "\n";
}
```

I get the following result in time with the master branch:

```
erlang:send/3                                    1100086  19.31  1312101

real    0m7.793s
user    0m7.764s
sys     0m0.217s
```

This means the actors communication is consuming 19% time sending messages between them. And this code is run by Zend PHP in less than 1 sec. So, this branch change actors by process dictionary for constants, includes, variables, context and functions and we get:

```
$ time ./ephp benchmark.php 

real	0m0.748s
user	0m0.717s
sys     0m0.070s
```

This code is run 10x faster than the master branch.