Issue #329 - Progress listener. Interrupt non-actual loadings if loaded less 75%.
Sample: Progress listener example in GridView
Sample: Built the latest snapshot
Merge branch 'master' into progress_listener

Conflicts:
	library/src/com/nostra13/universalimageloader/core/ImageLoader.java
Non-actual downloads will be interrupted (if loaded less than 75%)
Merge branch 'progress_listener'
Renaming: LoadingProgressListener -> ImageLoadingProgressListener
Merge branch 'progress_listener'