New Formula: Dynare 4.4.3

Following up on #697, we have created a make install.

Given that we already waited 4 months to have #697 reviewed, I would greatly appreciate it if you could move this up on your priority list.
Sorry, I'm not a Ruby programmer (let's say I'm not even a novice Ruby programmer). What is the ```prefix``` and how do I store something there? Can you point me to an example formula that does this?