Revert using no window background.
Merge pull request #504 from square/dimitris/revert-no-background

Revert using no window background.
Add logging throughout Picasso
Update CHANGELOG for 2.3
Merge pull request #510 from square/dimitris/23

Update CHANGELOG for 2.3
Merge pull request #509 from square/jw/logging

Add logging throughout Picasso
If OkHttp is present, require 1.6.0 or better.
Merge pull request #517 from square/jwilson_0527_okhttp_16

If OkHttp is present, require 1.6.0 or better.
Mention OkHttp 1.6+ in the change log.
[maven-release-plugin] prepare release picasso-parent-2.3.0
[maven-release-plugin] prepare for next development iteration
Update release date for 2.3.0
Fix deprecated constructors for Downloader.
Merge pull request #519 from square/dimitris/fix

Fix deprecated constructors for Downloader.
Update 2.3.1 CHANGELOG.
[maven-release-plugin] prepare release picasso-parent-2.3.1
[maven-release-plugin] prepare for next development iteration
Picasso.with() should be synchronized
Merge pull request #521 from Macarse/macarse/threadSafeSingleton_2

Picasso.with() should be synchronized
Merge branch 'master' into disk-cache

Conflicts:
	picasso/src/main/java/com/squareup/picasso/BitmapHunter.java
	picasso/src/main/java/com/squareup/picasso/Picasso.java
	picasso/src/test/java/com/squareup/picasso/ImageViewActionTest.java
	picasso/src/test/java/com/squareup/picasso/NetworkBitmapHunterTest.java
	picasso/src/test/java/com/squareup/picasso/PicassoTest.java
	picasso/src/test/java/com/squareup/picasso/RemoteViewsActionTest.java
	picasso/src/test/java/com/squareup/picasso/RequestCreatorTest.java
	picasso/src/test/java/com/squareup/picasso/TargetActionTest.java