docs(README_fr_FR): add extra pseudo processors for path computation
chore(package.json): update to version 0.4.0-beta.3
chore(package.json): lodash is used in lib/Dgeni.js, it's not a dev dependency

Closes #96
chore(gen-docs.js): expose dgeni as a command line tool via npm

Closes #97
fix(gen-docs.js): `startsWith()` is not ES5 compatible

This was leftover from when we were using es6-shim in dgeni. Now that has
gone we must go back to using `indexOf()` instead.

Closes #97
feat(Dgeni): add `configureInjector` method

This change helps to support easier unit testing of Packages where you
may wish to get the injector to instantiate a service or processor for
you without actually running any processing.
feat(gen-docs): add log option to CLI

If you `--log {level}` or `-l {level}` you can override the logging level via
command line - independent from settings in other packages. This is a opt-in.
If you don't use `--log {level}` or `-l {level}` nothing changes.
fix(gen-docs.js): remove unnecessary reference to base package

See #98
docs(Dgeni): add documentation for `configureInjector()`
docs(README): describe command line tool
chore(package.json): update to version 0.4.0-beta.4
fix(Dgeni): handle validation and processor errors better

There must surely be a nicer way to get promises to do what this is doing!