add advice about delaying dygraph instantiation when using excanvas.
add advice about delaying dygraph instantiation when using excanvas.

davidmsibley/dygraphs,Yong-Lee/dygraphs,socib/dygraphs,davidmsibley/dygraphs,vhotspur/dygraphs,socib/dygraphs,danvk/dygraphs,witsa/dygraphs,grantadesign/dygraphs,panuhorsmalahti/dygraphs,grantadesign/dygraphs,reinert/dygraphs,klausw/dygraphs,jmptrader/dygraphs,mariolll/dygraphs,pshevtsov/dygraphs,jmptrader/dygraphs,davidmsibley/dygraphs,pshevtsov/dygraphs,mcanthony/dygraphs,Akiyah/dygraphs,mantyr/dygraphs,mariolll/dygraphs,danvk/dygraphs,mantyr/dygraphs,reinert/dygraphs,vhotspur/dygraphs,petechap/dygraphs,mcanthony/dygraphs,panuhorsmalahti/dygraphs,klausw/dygraphs,Yong-Lee/dygraphs,panuhorsmalahti/dygraphs,witsa/dygraphs,socib/dygraphs,pshevtsov/dygraphs,petechap/dygraphs,jmptrader/dygraphs,klausw/dygraphs,timeu/dygraphs,klausw/dygraphs,panuhorsmalahti/dygraphs,jmptrader/dygraphs,mcanthony/dygraphs,timeu/dygraphs,mantyr/dygraphs,kbaggott/dygraphs,panuhorsmalahti/dygraphs,vhotspur/dygraphs,witsa/dygraphs,reinert/dygraphs,Akiyah/dygraphs,mcanthony/dygraphs,Akiyah/dygraphs,danvk/dygraphs,Yong-Lee/dygraphs,mantyr/dygraphs,petechap/dygraphs,kbaggott/dygraphs,mantyr/dygraphs,petechap/dygraphs,mariolll/dygraphs,timeu/dygraphs,vhotspur/dygraphs,reinert/dygraphs,kbaggott/dygraphs,witsa/dygraphs,grantadesign/dygraphs,pshevtsov/dygraphs,timeu/dygraphs,danvk/dygraphs,jmptrader/dygraphs,Akiyah/dygraphs,danvk/dygraphs,mcanthony/dygraphs,mariolll/dygraphs,grantadesign/dygraphs,davidmsibley/dygraphs,petechap/dygraphs,reinert/dygraphs,davidmsibley/dygraphs,kbaggott/dygraphs,kbaggott/dygraphs,grantadesign/dygraphs,Yong-Lee/dygraphs,klausw/dygraphs,mariolll/dygraphs,socib/dygraphs,Akiyah/dygraphs,Yong-Lee/dygraphs,timeu/dygraphs,witsa/dygraphs,pshevtsov/dygraphs,vhotspur/dygraphs