New formula for euca2ools, commandline tools for interacting with AWS or Eucalyptus. This is my first formula, critique is encouraged.
Address comments from @mikemcquaid.

1. Formatting fixes.
2. No more brew version of pypy,openssl,libxml2, and brew-pip. system versions will be used where needed
3. Install lxml Python module with install_args rather than with pip
4. add bin.env_script_all_files

NOTE:  Did not change the test because it is the simplest test. There is no "euca2ools" binary thus there is no euca2ools --version. euca2ools-version is a euca2ools command that is the equivalent.
Address additional comments from @mikemcquaid.

1. Formatting fixes (split line over 80 chars)
2. Stable versions of requestbuilder and requests used
3. Modified test from printing version to displaying help.
Address final nits from @mikemcquaid.

1. Formatting fixes (double quotes everywhere!)
2. Updated C flags comment
euca2ools: add 3.0.2 bottle.