integrate changes from git issue. closes #568
integrate changes from git issue. closes #568

stea4lth/TimelineJS,wangjun/TimelineJS,landsurveyorsunited/TimelineJS,stea4lth/TimelineJS,deenjohn/TimelineJS,1modm/TimelineJS,djaney/TimelineJS,angeliaz/TimelineJS,1modm/TimelineJS,ycaihua/TimelineJS,anxintiancai/TimelineJS,LauraHilliger/TimelineJS,pom95/timeline,ryekee/TimelineJS,ryekee/TimelineJS,anxintiancai/TimelineJS,NUKnightLab/TimelineJS,JoaquinSiabra/TimelineJS,ycaihua/TimelineJS,deenjohn/TimelineJS,james-logan/TimelineJS,landsurveyorsunited/TimelineJS,wangjun/TimelineJS,anxintiancai/TimelineJS,deenjohn/TimelineJS,JoaquinSiabra/TimelineJS,landsurveyorsunited/TimelineJS,djaney/TimelineJS,LauraHilliger/TimelineJS,CrossLead/TimelineJS,zstao/TimelineJS,noikiy/TimelineJS,pom95/timeline,james-logan/TimelineJS,matt-edgedesign/Timelinejs,zstao/TimelineJS,noikiy/TimelineJS,ycaihua/TimelineJS,matt-edgedesign/Timelinejs,JoaquinSiabra/TimelineJS,noikiy/TimelineJS,matt-edgedesign/Timelinejs,1modm/TimelineJS,james-logan/TimelineJS,pom95/timeline,LauraHilliger/TimelineJS,stea4lth/TimelineJS,NUKnightLab/TimelineJS,angeliaz/TimelineJS,zstao/TimelineJS,ryekee/TimelineJS,CrossLead/TimelineJS,djaney/TimelineJS,wangjun/TimelineJS,NUKnightLab/TimelineJS