Added jrnl formula

Hi there, 

I added a new formula for [jrnl](http://maebert.github.io/jrnl/) following your `contributing` guidelines.
It installs on a mavericks host and runs the test correctly.

If possible, please merge.

Thanks for your work.
You need to do this for the libexec site-packages as well or the PYTHONPATH the formula writes won't include the libexec site-packages and jrnl won't know how to find the pycrypto you're installing when you launch it.