Etherpad 1.4.0

Brings in etherpad 1.4.0

The toolbar is now configured through setttings.json. This also opens up the possibility of pumping logs from etherpad directly to syslog via log4js but isn't included in this PR just yet.

The configuration is backwards compatible with 1.2.91.

I've deployed this on http://oae.oae-release0.oaeproject.org