Upgrade dns/wdns to version 0.10.0:

• Handle corner case of NSEC3 hash field with length zero.
• Preserve name case when parsing rdata strings.
• Fix printing of bitmap entries for rrtypes larger than 255. Improve rrtype sorting.
• Preserve character-string boundaries when formatting TXT rdata.
• Add ./configure --with-coverage option to build with code coverage and make targets: clean-coverage to remove the coverage data and results and report-coverage to generate report (after running the code such as with "make check").
• Configure check for python which is used to generate some of the C code.
• Lots of compiler warning cleanups.
• Unit testing improvements and additional tests added.
• Added library versioning API: wdns_get_version() and wdns_get_version_number() available at run-time and WDNS_LIBRARY_VERSION and WDNS_LIBRARY_VERSION_NUMBER for compile-time.

Add python as a build dependency.

Pet portlint (USES vs. USE ordering).

Sponsored by: Farsight Security Inc.