Allow user to set custom STUN server in UI.
Replace core.iceServers with core.webrtcPcConfig
Allow custom RtcNet configs + show confirmation.
Merge remote-tracking branch 'origin/dev' into lucyhe-stun_config_in_ui
Use same STUN server for socksToRtc and rtcToNet.
Add support for Polymer core elements.
Add core-icons to bower.json.
Allow user to reset STUN servers to default.
Change setStunServer logic.
Merge remote-tracking branch 'origin/dev' into lucyhe-stun_config_in_ui
Fix comments + remove unused code.
Update const variable names.
Merge with dev
Added socksRtcPcConfig & rtcNetPcConfig variables.
Merge branch 'dev' of https://github.com/uProxy/uproxy into lucyhe-stun_config_in_ui
Comments + CSS edit.
Edit STUN server confirmation text.
Merge pull request #617 from uProxy/lucyhe-stun_config_in_ui

UI for setting custom STUN server. Include core-elements in UI.