add memoryCachePercent method
fix a bug
use Runtime.getRuntime().maxMemory() instead of memoryclass
remove ununsed import
fix a bug
Readme: Added app using UIL
Allow Application to Add the permission "WRITE_EXTERNAL_STORAGE"
Readme: Added apps using UIL
There was an issue where "lastUsageDates" in LimitedDiscCache had some
cache files that were not in cache directory, so LimitedDiscCache wasn't
removing the cache files. 

It usually happened in ListView, so to solve this issue, I modified
removeNext() method in LimitedDiscCache.
Readme: Added apps using UIL
ILC.memoryCachePercent() -> memoryCacheSizePercentage(), refactored
method
Issue #301 - NPE in ImageLoaderEngine
Not null executors, shutdown built-in executors on engine stop
Refactored StorageUtils
Clean code
Issue #309 - Introduced bitmap processor for disc cache (in ImageLoaderConfiguration.discCacheExtraOptions(...))
  Issue #249 : Buffer size 8K -> 32K
Sample: Added TargetApi annotation
  Issue #252 - Introduced DisplayImageOptions.cacheInMemory(boolean), .cacheOnDisc(boolean), resetViewBeforeLoading(boolean)
  Deprecated appropriate methods without boolean param
Sample: Not use deprecated methods
  Issue #270 - Printing log messages should be configurable
  Added L.disableLogging() and .enableLogging() to completely on/off UIL's logs