Implements a profiler that keeps track of the time each file takes to render.

A file can be rendered or compiled multiple times in the same stage (e.g when being included), so the compiler hashes each file and metadata to distinguish between those.

After the compilation is finished, a profiler report is generated and can be accessed at /profiler.html.

The profiler should only run in development and can be disabled by setting:

config :still, profiler: false