Update integration script for Apache 2.4

Apache 2.4 requires site configuration files to have a ".conf"
extension, and Apache 2.2 does not want the extension. Add logic to
figure out the right name for the file so we can run the tests against
both versions of Apache.

Fixes bug: #1334326

install required libraries for mixed c things

use build-dep to install the required libraries needed for
the python build deps. Without this we can get cryptic library
compilation issues.

And use ccache explicitly

Change-Id: Ia750e4221b119097521cf373752aae364759913b squashed
into this one because we can't move forward without both.

Co-Authored-By: Sean Dague <sean@dague.net>

Change-Id: I5ab8898bd3cc2de18681fe3262cb784f7d9519ab