print error message on unhandled rejection for non-chrome

fixes #570
if notebook load fails somewhere after the gist part, don't keep trying

we were going into a death loop on safari because of some random other
incompatibility in our code

for #809
remove obsolete performance log

it was bombing on safari
fixes #809
Merge branch 'hotfix/1.1.2' into develop

Conflicts:
	htdocs/editor_tab.js
	htdocs/js/rcloud_bundle.min.js