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.
Merge pull request #316 from ncoolz/master

Handle deletion of files from disc cache, keep lastUsageDates actual.