provision: it's probably safe to forget about Python 2.6 in 2017

provision: target newer Nginx versions (>1.9.5 in this case)

provision: use become instead of sudo

pipelines: install Mercurial to check builds and SRI Was lost after provision tests were removed from pipelines.

pipelines: switch to Xenial, use Ansible from distro repos

Make: use npm update for devel target package.json says we want coffee-script >= 1.6.1, so that's what `make devel` should install (the newest version): since .js source is tracked, there's no risk of running into breaking changes in coffee-script outside of test environment. But running into such changes during tests is OK and even potentially desirable.

pipelines: it's too expensive to test provisioning

pipelines: retain node_modules between runs

updatesri: backslash is not an escape character for urls

index: make input fields below contact list and chat log look separate