use external jdns

Added qcm module to check for external qjdns. If external qjdns
not found will be used bundled version. Also bundled qjdns will be
used on Windows and Mac OS X without checking for external qjdns.
Merge pull request #21 from drizt/external_jdns

use external jdns
fixed include path
Merge pull request #22 from drizt/include_path

fixed include path
small qjdns qcm module fix with defines