Merge remote-tracking branch 'origin' into save_tag_info
return empty result if filter = 1.  TODO check filter before populating the map.
added tags to stucts.
Merge remote-tracking branch 'origin/master' into save_tag_info

Conflicts:
	src/mjolnir/pbfgraphbuilder/pbfgraphbuilder.h
clean up.
fixed merge issue.
Merge pull request #59 from mapzen/save_tag_info

Save tag info