Use NSCache instead of a dictionary for the memory cache.
Fixed Alpha chanel detection when decoding images.
Merge pull request #203 from Stigec/master

Fixed Alpha detection when decoding images.
Send downloader as part of notification.
Merge pull request #183 from gotosleep/502f74042f10aa3a34d95a5e3f3e9a6500471554

Use NSCache instead of a dictionary for the memory cache.
Add NSCache's cost argument
Fix example app
Change deployement target to 4.x as NSCache wasn't available in 3.0
Revert "Fixed Alpha chanel detection when decoding images."

This reverts commit e6ede1104cea39f2034ec5a1644e2d2082cc57bd.
Fixed Alpha chanel detection when decoding images.
Fix alpha handling in image decoder (fix #204)
Merge pull request #205 from triposo/send-downloader-with-notification

Send downloader as part of notification.
Add cancelAll method (fix #168)
First beta of SDWebImage 3.0

This version is a rewrite of the lib using iOS 5.0 as minimum target.
The lib as thus been refactored to use blocks/GCD from the ground up.
As a consequence, all delegate code style has been removed. The result
is a lot less lines of code and more flexibility.
Add who use it section
Remove outdated motivation section
Add "How is SDWebImage better than X?" wiki link
Add Licenses section
Fix typo in license URL
Fix wrong cache policy used (fix #211)