Add .gitignore file
Merge branch 'master' of https://github.com/dnsviz/dnsviz
Move tcp setting to query instead of response.  Also, track TCP and UDP
queries and server responsiveness more effectively.
Handle source port modifications implicitly by error code, rather than
by adding a new member variable.
Note the change the made the difference in responsiveness for a given
query/response.
Use nxdomain_name and nxrrset_name to identify name analysis object.
Use new accuracy of get_name() to eliminate "not None" checks
Add ClearDOOnTimeoutHandler to TCP diagnostic queries.
Update comments indicating inferred actions.
Add change EDNS version action
Break out EDNS/DO errors into more meaningful errors for more detailed
and accurate diagnostics.
Fix a few bugs overlooked in previous commit
Support more fine-grained DNSSEC response analysis

Distinguish between cases in which RRSIGs were missing from the server
and when they simply could not be retrieved.
Match incoming DNS responses more robustly

Case sensitively compare the question in the response with the question
in the request only if there *is* a question in the response (could be
SERVFAIL).
Distinguish valid responses

Distinguish valid responses from invalid responses when indexing the
responsiveness of servers and what changes caused responsiveness to
change.
Use method for checking valid response
Don't process incomplete responses
Add effective_tcp instance var to response
Make EDNS responsivness tests more robust
Break down analysis functions

Break down analysis functions into more manageable sizes and for
improved code re-use.