Closes issue #16
Bugfix Method set_dirty_cache_entry of class StoreSyncThread, to prevent that the cache entry is deleted immediately after setting it dirty
Modify constructors of classes MultiprocessingCachingStore, and ChunkMultiprocessingCachingStore, if the parameter cache_expiration_time is smaller than 30 seconds
Modify method write of class VirtualConfigFile, to set the default for the cache expiration time to 30 seconds
Bugfix method flush of class PyFuseBox, to raise ENOSPC error if there is not enough free space to store the file - get the correct file size
Bugfix logging issue with third party module parsedatetime; logging configuration has been overwritten by CloudFusion and needed to be reconfigured so that no output is generated