Fix RAT issues for 1.1

* Adds x509_check_host.{cc,h} to the RAT exclude list. These files are
  copied from OpenSSL which has a compatible license, and which has been
  noted already in the top-level LICENSE/NOTICE files.
* Adds an Apache license header to the sample README.adoc.

Change-Id: I107b6c9e3c8e928c74a10e6e08ef7b9cad066806
Reviewed-on: http://gerrit.cloudera.org:8080/5076
Reviewed-by: Jean-Daniel Cryans <jdcryans@apache.org>
Tested-by: Todd Lipcon <todd@apache.org>
2 files changed