Configure cctbx.xfel from existing Phenix install

Much of the code to run cctbx.xfel is already bundled in the latest phenix installers. The only missing package is DIALS. Here's how to get cctbx.xfel configured from an existing Phenix installation.

Note: this only applies to processing individual stills. Functionality to read XTC streams from LCLS is not included when using this procedure.

Once Phenix is installed and sourced correctly:

 cd <path to phenix installation>/modules
 git clone git@github.com:dials/dials.git
 cd ../build
 libtbx.configure xfel
 make
 make

prime.postrefine, one of the merging and scaling programs provided with cctbx.xfel, requires scipy. This can be installed with this command:

libtbx.python -m easy_install scipy

On linux, this may require openssl to be installed, if it's not already:

yum install openssl098e