undefsafe that bad boy.

Fixes #1643
Merge pull request #1644 from jsbin/fix/1643

Don't blow up when configs don't exist
Fixed #1638

Also (should) fix @phuu's issue with tab size.

Though, if I'm honest, I'm not 100% sure *why* this works...
Updated stylus
x-frame-options applied to full bin output
Use pageVisibiltiy API to disconnect eventsource

And reduce number of open connections from client
Fixed #1174

Ensure the *old* bin is going in to do the bump lookup. Somehow it was using the latest bin (suspect the line that changes the req.bin, via spike/index.js)
Merge pull request #1647 from jsbin/fix/1174-fix-spike-confusion

Fixed #1174
Merge pull request #1651 from jsbin/fix/no-iframes-please

x-frame-options applied to full bin output
Merge pull request #1650 from jsbin/feature/es-disconnect-on-hide

Use pageVisibiltiy API to disconnect eventsource
Merge pull request #1649 from jsbin/fix/1638

Fixed #1638
Somehow completely fucked that up.
Merge pull request #1653 from jsbin/fix/1652

Somehow completely fucked that up.
Merge branch 'master' into feature/scss

Conflicts:
	package.json
	public/js/vendor/stylus.js