Explicitly cast path parameter "id" from string to number because the
REST transport does not implement parameter coercion yet.
See #750

This change removes the following warnings from `npm test` output:

    WARNING: id property cannot be changed from 3 to 3 for model:Todo
    in 'before save' operation hook

    WARNING: id property cannot be changed from 3 to 3 for model:Todo
    in 'loaded' operation hook

This is a follow-up to #964.

Two config files are in place now:
- tslint.build.json for CLI build scripts
- tslint.json for vscode

 - Move any REST-related setup from app.start() back to app constructor.
 - Update the project template to use RestApplication too
 - Update authentication README to use RestApplication

Rework example-getting-started to use sinon from @loopback/testlab
instead of importing it directly.

* fix(core): decouple app config from assembly

* fix(core): update the readmes

* fix(core): add comments

* fix(rest): rebase against RestApplication PR

* fix(core): get rid of array registration

This PR is a follow-up to the following issue based on review comments:
#939

- Demonstrate how to plug in a different log (console vs memory)
- Switch to @loopback/metadata for decorator implementation
- Remove log level provider as it's supposed to be contributed by the app

The exercise also exposes a few needs:
1. Support for optional dependency so that we can fall back a default
  implementation (or a better way)
2. Allow a component to bind artifacts beyond providers

* fix(cli): remove copyright header from generated app

use `.template` extension for templates. Rename during project generation. Removes copyright headers from templates.

Fixes #944

* fixup! apply feedback - use RegExp for matching instead of extname

Clean up per-package `package.json` files and remove dependency on
`mocha` in all places where `lb-mocha` is already in use.

 - Use npm scripts instead of invoking lerna directly
 - Clean up task names

* feat(cli): switch .template to .ejs

* revert: undo removing dist6 from templates

Follow up from #996 and related to dropping Node 6 support. CLI template had references to `dist6` folders which are no longer generated.

The check for equality on example packages after cloning prevents
update of the contents of those packages, since they are no longer
equivalent! As a result, we are disabling this test for now until
we can come up with something that suitably validates the
behaviour we expect, but in a way that doesn't prevent future
changes from passing tests.

Break up the pieces of the tutorial so that they can be served as individual links on LoopBack.io
under the LB4 docs.

re #729

 - @loopback/authentication@4.0.0-alpha.33
 - @loopback/cli@4.0.0-alpha.23
 - @loopback/context@4.0.0-alpha.32
 - @loopback/core@4.0.0-alpha.34
 - @loopback/example-getting-started@1.0.1-alpha.7
 - @loopback/example-hello-world@4.0.0-alpha.4
 - @loopback/example-log-extension@4.0.0-alpha.7
 - @loopback/example-rpc-server@4.0.0-alpha.5
 - @loopback/openapi-v2@4.0.0-alpha.11
 - @loopback/repository-json-schema@4.0.0-alpha.8
 - @loopback/repository@4.0.0-alpha.30
 - @loopback/rest@4.0.0-alpha.26