templates: use loopback-boot 2.0.0-beta2
Rename ComponentDefinition to Facet.
Rename ComponentModel to ModelConfig
Rework templates and model definitions

Refactor the `server` component template into a `server` facet template
that is a part of `api-server` component template.

Move model definitions from to `common/models`
Remove PackageDefinition from Facet

There is only one package.json file per component now.

The new layout:

```
project/
  package.json
  common/
    models/
    # no package.json
  server/
    model-config.json
    # etc.
    # no package.json
```
Refactor `config.json` into FacetSetting

Before this change, all `config.json` entries were added to the `Facet`
entity as properties.

This change adds a new entity `FacetSetting` that represents a single
entry in `config.json`.
Fix issues discovered during review

 - rename 'component' to 'facet' in few places
 - add missing "Facet hasMany" relations
 - fix coding style issues
Merge pull request #82 from strongloop/facets

[3.0] Rework Components into Facets