Significant upgrade since last version

Only allow one instance of InfoWindow at any time
User must upload at least one photo along with the news
If there are less than four photos for one news, it loads the default
photo
Users can upload news with photos, and submit to the server, the sever
than load both the description and photos of the news
There are significant changes since last update.
Environment prerequisite:
Steam upgraded to v0.6.2
Dart Editor 0.4.3_r20602
Dat SDK 0.4.3.5_r26062
Server: main.dart
Client: 10.1.1.11:5050
The localhost has changed to 10.1.1.11:5050 for testing in my case.
You must use r20602 version and Stream v0.6.2 to in order to run the
codes correctly.