function deleteMetadataForEntry(self, key) {
			var iIndex = self._metadata.__byKey__[key];
			delete self._metadata.__byKey__[key];
			delete self._metadata.__byIndex__[iIndex];
			if (self._metadata.timestamps[key]) {
				delete self._metadata.timestamps[key];
			}
			seekMetadataLRU(self);
		}
Deletes all metadata for given key
@param self the instance
@param key the key for the entry