1. Re-enable DTD validation once
   https://github.com/UweSchmidt/hxt/issues/15 is fixed.

2. Write a test for test/xml/Odds_XML-long-import.xml once it no
   longer takes 10 minutes to import (Postgres only?).

3. Add support the the second type of weatherxml (see man page).

4. We have DTDs but no sample XML for the following SportInfo types,
   which have therefore been left unimplmented for now:

   * Cbask_Indv_No_Avg_XML.dtd
   * Cbask_Indv_Shooting_XML.dtd
   * CBASK_StealsXML.dtd
   * Cbask_Team_Scoring_Rebound_Margin_XML.dtd
   * Cbask_Team_Scoring_XML.dtd
   * Cbask_Team_Shooting_Pct_XML.dtd
   * NFLGrassTurfDomeOutsideXML.dtd
   * NFLInterceptionLeadersXML.dtd
   * NFLPassingLeadersXML.dtd
   * NFLReceivingLeadersXML.dtd
   * NFLRushingLeadersXML.dtd
   * NFLTackleFFLeadersXML.dtd
   * NFLTopKickoffReturnXML.dtd
   * NFLTopPuntReturnXML.dtd
   * NFLYardsXML.dtd
   * NFL_PuntingLeaders_XML.dtd

5. The following DTD types were handled (in some form) by the old
   FeedGrabber. They are not yet handled by htsn-import (some may not
   be valid):

   * AutoRacingDriverList
   * AutoRacingGridXML
   * CBASK_Individual_Stats_XML
   * Cbask_Roster_XML
   * cbaskteamschedulexml
   * CBATeamScheduleXML
   * CFLTeamScheduleXML
   * CFLTotalTeamScheduleXML
   * earlylineXML
   * Minor_Baseball_TeamScheduleXML
   * MinorLeagueHockeyTeamScheduleXML
   * MLB_Boxscore_XML
   * MLB_earlylineXML
   * MLB_IndividualStats_XML
   * MLB_Probable_Pitchers_XML
   * MLB_Roster_XML
   * mlbteamschedulexml
   * mlsteamschedulexml
   * NBA_Boxscore_XML
   * NBA_Individual_Stats_XML
   * NBA_Roster_XML
   * nbateamschedulexml
   * NCAA_Basketball_Boxscore_XML
   * NCAA_FB_TeamScheduleXML
   * NCAAHockeyTeamScheduleXML
   * NFL_Boxscore_XML
   * NFL_CompBox_XML
   * nfldepthchartxml
   * nflteamschedulexml
   * nhlteamschedulexml
   * WCBaskTeamScheduleXML
   * WNBA_Boxscore_XML
   * WNBA_Individual_Stats_XML
   * WNBATeamScheduleXML

6. Add a note about the NULL vs. empty string policy in the man page.

7. Create an XmlImportFkTeams class and use it for JFile, Odds, and
   ScheduleChanges.

8. Consolidate all of the make_game_time functions.

9. Document how to get an empty database set up (import test xml then
   delete).

10. Add/update dbschema diagrams for JFile, Odds, and ScheduleChanges.