With this commit, we introduce a benchmarking infrastructure: a new
controller, accessible at the route /web/benchmarks which will render a
new template (web.benchmark_suite).

This template uses benchmark.js and qunit.js to display a list of
benchmarking informations.  For example, the number of op/s for
instantiating and destroying a list view.

I hope that this is the start of the beginning of taking the habit to
check our JS code performance sometimes, and making sure we do not have
large regression without a good reason.