Unbreak make install for apache config files

The new install process installs the Apache sample configs into the
DOCDIR for Evergreen, with the expectation that packagers will pick up
the examples from the doc directory and that users will eventually be
expected to copy them from there, rather than from the source tree.

However, currently the Apache 2.2 and 2.4 sample configs have the same
names, and that causes a conflict at "make install" time. Kudos to Jason
Stephenson for catching this. The temporary solution is to rename the
Apache 2.4 files to avoid the conflict; longer term, we need to teach
make install to only make & install the files that are pertinent to the
environment on which it was built (either Apache 2.2, or Apache 2.4).

Signed-off-by: Dan Scott <dscott@laurentian.ca>
Signed-off-by: Jason Stephenson <jstephenson@mvlc.org>