tquery.world and default renderer

[jeromeetienne]

• set .webglNeeded : true by default
• depends on an url varaible to force/allow canvas
• in the message "no webgl too bad", put a link to the "allow canvas" url
• thanks to joeytwiddle on #bbg irc

[joeytwiddle]

The goal here is to provide the software renderer for those users who need it, and who would otherwise never see any ThreeJS apps running!

But at the same time, since software renderer can be very heavy and lock up slow browsers, we don't want to switch straight to it by default.

So a path is made available for the user to Accept to use software renderer. Nice idea to do this by reloading the page with a magic & or # parameter.

Thanks jetienne!