rename renderTo to renderUpTo; add visibilityChanged/displayChanged emits
rename renderTo to renderUpTo; add visibilityChanged/displayChanged emits

kerrishotts/Mastering-PhoneGap-Code-Package,kerrishotts/Mastering-PhoneGap-Code-Package,kerrishotts/Mastering-PhoneGap-Code-Package,kerrishotts/Mastering-PhoneGap-Code-Package