Feature/ngui doublerange fix

input[type=range] behavior changed with angular 1.3

this PR fixes doublerange directive, but at same time gives up on using html5 mode in coopr because that UI is not practical for the end user.
a mystery is why this doesnt seem to be needed anymore. I suspect it has to do with `input[type]` attr switching from number to range on the fly? Is it a feature or a happy bug? We should avoid using html5 mode until we figure this out.