Added commentCount field to BlogPost.

-Fixed the broken implementation of the builder pattern for BlogPosts.
Now the constructor is private and new instances should be created by
calling Builder.build().
-Moved the StreamItemComparator into StreamItem class and made it
public.  
-Changed FakeDataSource to use the updated BlogPost.Builder
Added new icon.
Finalized launcher icon, and added pretty data for the poster screenshot
Merge branch 'master' of
https://github.com/dattorz/CascadeLMS-Android.git

Conflicts:
	src/org/cascadelms/data/models/BlogPost.java
	src/org/cascadelms/data/models/StreamItem.java
	src/org/cascadelms/data/sources/FakeDataSource.java
Re-added new icons after merge problems.