prototype is extended. Although OpenLayers is not designed to work when this
fundamental violation of Javascript is in place, we can at least not fail
so miserably in this case: this gets us back to a similar level of
functionality as we had in 2.5. This was brought up by a user working on
a viamichelin layer, which apparently extends the object prototype (bad!),
and fixed in conjuction with tschaub. r=pgiraud,tschaub (Pullup #1502)
git-svn-id: http://svn.openlayers.org/trunk/openlayers@6832 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
