Initial work on fixing the viewing of events for different years.
fix headers to be accurate for different years
update sort by event type & date to actually sort (and group) by event type
always default event view to week 1, regardless of which tab index it is
display all years since 1992 in action bar spinner
tabs finally work correctly across years. wooho!
bugfix: don't show items in event info that aren't set
Merge branch 'master' into fix_event_years

Conflicts:
	android/src/main/java/com/thebluealliance/androidclient/background/PopulateEventList.java
fix #72
close #75
Added JsonNull checks to fix a crash when loading events with teams without a team name or location.
Added a placeholder name in the Teams tab in an event for those teams without a name, similar to what was done in the Teams activity.
Added extra NPE check in PopulateEventInfo to fix a possible crash.
Added size check when getting OPRs, since some events have OPR keys with nothing in it. This resulted in a blank "Top OPRs:" being shown. This also resulted in some events not showing "Top OPRs:" despite having stats.
Added more JsonNull checks to fix some crashes from spamming event year changes.
Didn't put a replacement date inside the JsonNull check in SimpleEventDeserializer, so it was throwing an IllegalArgumentException instead. Woops, fixed!
Changed match scores to strings so that unknown scores appear as "?" like the TBA site.
Fixed OOB exception when viewing match lists/matches with two teams to an alliance (or none in some cases). Only add a third team text/touch listener if there are three teams in an alliance. Otherwise, leave the third slot blank. Doesn't support a 4v0 match for now. However, there isn't any match info from any of the 2001 regionals yet (the only year when 4v0 matches occurred) and I'm not sure if there will be in the near future.
Shifted a null check to fix a NPE crash when trying to view a blank activity/intent in the rare case that an event is still loading info even after the loading spinner goes away.
Fixed the constant in FIRST_COMP_WEEK that caused a blank 'Week 0' to appear when viewing events for 2012. (#78)