Icons stylesheet should not use query-string for hash

[yngvebn]

Several browsers and loadbalancers cache fonts quite hard, and will often ignore queryparams, which means icons.ttf?164ae04e6a0d14accac65bfe1939c817 will often not cause the browser to reload the font-file. If icons are added, this will end up with wrong icons showing up in the UI.

The solution would be to add the hash to the filename itself, like so icons.164ae04e6a0d14accac65bfe1939c817.ttf