mod_base: use window.location.host for websocket stream, unless configured otherwise.
Also add try/catch around websocket connect, to catch potential IE10 security exception.

(cherry picked from commit 23301e45d5ebc891fa3d3f3653fc147a3e4d3247)

Conflicts:
	modules/mod_base/lib/js/apps/zotonic-1.0.js