Adding "Mailparse" extension

Hello,

This should add the ability to use the "mailparse" extension.
I tested it on Ubuntu 14.04 with PHP5.5.9.

I do have an issue: I have to use `/usr/sbin/php5enmod mail parse` to see the mailparse module listed in when doing a `php -m`
I'm not entirely sure if that's meant to be, so any guidance is welcome!