main() returns void
Use ng-swtich for the conditional display of Loading message

- Only show “Recipe Details” heading when there is a recipe (like in
the other chapters).
- Use opportunity to introduce `ng-switch` for the conditional display
of the "Loading ..." message.
- Propagate changes to chap. 6 -7 .
Merge pull request #90 from chalin/patch-0226-chap5-ng-switch

Use ng-swtich for the conditional display of Loading message
Merge pull request #88 from vicb/patch-1

main() returns void
rating component cleanup
cleanup the tooltip directive
cleanup the category filter
Adding pubspec.lock - working versions !
cleanup ch06 & 07 components
cleanup routing
cleanup service
misc minor cleanup
Update ch07 README.md

based on previous chapter templates
Merge pull request #91 from vicb/lock

Adding pubspec.lock - working versions !
Merge pull request #92 from vicb/cleanup

Some cleanup across all chapters
refactor(ch07): simplify code

see https://github.com/angular/angular.dart.tutorial/pull/92#discussion-
diff-10179304
Merge pull request #93 from vicb/createInj

refactor(ch07): simplify code
fix(Chapter_05): add recipe id to recipes.json

Chapter 5 code reads an `id` from the JSON map data, but there is no
such field. It doesn’t really affect the functionality since the id is
not used until the next chapter. The `id` field is present in Chapter
6, hence this change also eliminates an unnecessary difference with
Chapter 6.
Merge pull request #95 from chalin/patch-0304-chap5-json-recipe-id

fix(Chapter_05): add recipe id to recipes.json
fix(recipe): follow new dart:convert.JsonCodec JSON encoding convention

- `recipe.dart` of Chap. 5:
  - Replace `toJsonString()` by `Map toJson()` as documented in
[dart:convert.JsonCodec#encode](https://api.dartlang.org/apidocs/channel
s/stable/#dart-convert.JsonCodec@id_encode)
  - Some code cleanup.
- Chap. 6 & 7 made to match updates to Chap. 5.