Uninteresting files that run on tool's startup (set up profilers, transpilers, etc) and exit (clean up code, flush the output).

ES2015 compilation for tool

There are two different configurations of Babel for the tools code:

• local development from git checkout
• running in production from a release

In the first case, it is enough to register Babel's hook for require. For the latter, this hook should be removed (#RemoveInProd) and the files should be explicitly compiled.

The listing of Babel-compiled files can be found in isopack.js, the Isopack#_writeTool method runs all the preprocessing when tools files are copied for a release package.