Update web/ samples to work with Flutter SDK (#134)

* add package:http dependency in dad_jokes

* add package:http dependency in filipino_cuisine

* don't build package:http demos until flutter/flutter#34858 is resolved

* update gallery

* update github_dataviz

* update particle_background

* don't build github_dataviz (uses package:http)

* update slide_puzzle

* update spinning_square

* update timeflow

* update vision_challenge

* update charts

* update dad_jokes

* update filipino cuisine

* ignore build output

* update timeflow and vision_challenge

* update slide_puzzle

* don't commit build/ directory

* move preview.png images to assets

* fix path url join

* update readme

* update web/readme.md

web/peanut.yaml

@@ -1,30 +1,16 @@
 # Configuration for https://pub.dartlang.org/packages/peanut
 
 directories:
-- charts/example/web
-- dad_jokes/web
-- filipino_cuisine/web
+- charts/web
+# package:http doesn't work yet: https://github.com/flutter/flutter/issues/34858
+#- dad_jokes/web
+#- filipino_cuisine/web
 - gallery/web
-- github_dataviz/web
+#- github_dataviz/web
 - particle_background/web
 - slide_puzzle/web
 - spinning_square/web
 - timeflow/web
 - vision_challenge/web
 
-builder-options:
-  build_web_compilers|entrypoint:
-    dart2js_args:
-    # Generate `.info.json` files for compiled libraries.
-    - --dump-info
-    # Reduces diffs between builds, but increases JS output size slightly.
-    - --no-frequency-based-minification
-    # Deployed example does not include Dart source. Not needed.
-    - --no-source-maps
-    # Enable all dart2js optimizations. Not recommended without thorough testing.
-    - -O4
-  build_web_compilers|dart2js_archive_extractor:
-    # Ensures .info.json file is preserved. Useful for tracking output details.
-    filter_outputs: false
-
 post-build-dart-script: _tool/peanut_post_build.dart