Quick fix test for sqlite different thread issue.

Found this solution on a stackoverflow thread.
I'm not sure if it fixes the problem as I can't replicate it
myself.

If you are getting this issue, please test this pull request

git remote add gubatron https://github.com/gubatron/OpenBazaar
git fetch gubatron
git checkout experimental-fix-sqlite-different-thread-issue-654

run openbazaar and let me know if the issue persists, or if now
this is causing even weirder issues.

This is far from the ideal solution, but it might fix the problem.

The right solution might be (if we need db fetched objects on another
thread) having a DB-querying thread which is responsible for performing
all DB fetch operations and keeping the consumable outputs
in a temporary container (dict or queue) which is then consumed by
other threads.
Disable sqlite same thread check. (Re:Issue #654)
Merge pull request #921 from gubatron/release-0.3.0

Disable sqlite same thread check. (Re:Issue #654)
Overwrite pystun server list.

* Non-responding servers in pystun's builtin list are causing node to
  crash upon starting up.
network_utils.stun_servers_status_report(server_list)

Given a list of stun servers, probes them and prints out
a report. Useful whenever we want to update the list of
STUN servers to use.
updated STUN server list.
Merge pull request #2 from gubatron/fix_STUN_check

network_utils.stun_servers_status_report(server_list)
Various build and style fixes.

* Rename list to _STUN_SERVERS.
* Remove stun.iptel.org
* Abstract get_NAT_status to work with a specific hostname.
* Remove summary report to enable better automation.
* Add a main function to call test_stun_servers.
Merge pull request #922 from Renelvon/fix_STUN_check

Overwrite pystun server list.