Fixed crash on Android 4.2.2 devices

Utils.calculateDiskCacheSize throws java.lang.IllegalArgumentException: Invalid path on Nexus 4 (Android 4.2.2) if cache directory doesn't exist. Calling cacheDir.mkdirs solves the problem
Merge pull request #44 from mironov-nsk/crash-fix

Fixed crash on Android 4.2.2 devices
Allow null placeholder.
Merge pull request #45 from square/jw/null-placeholder

Allow null placeholder.
Mention remote URL first.
Whitespace is for communists.
Prepare version 1.0.2.
[maven-release-plugin] prepare release picasso-parent-1.0.2
[maven-release-plugin] prepare for next development iteration
Add centerInside option.

Added centerInside method to RequestBuilder.
Additionally, PicassoDrawable will always center the Bitmap inside it.
Merge pull request #48 from SimonVT/center-inside

Add centerInside option.
FQCN not needed.
Use Uri to manage paths internally.
Use the StatsHandler
Merge pull request #51 from scompt/use_StatsHandler

Use the StatsHandler
Merge pull request #50 from square/jw/uri

Use Uri to manage paths internally.
Drop the decode lock on stream handling.

This lock was actually detremental to the speed since we piped streams directly to the Bitmap decoder rather than through an intermediary byte array. Thus we potentially blocked all bitmap decoding while waiting on a single stream.

Only lock decoding from Bitmap to Bitmap since that is where the real potential to OOM exists.

Closes #49.
Merge pull request #57 from square/jw/pop-lock-and-drop-it

Drop the decode lock on stream handling.
Add support for contact photo loading.
Add contact photo loading sample.