Dependencies in node export should be in constant ordering

Currently when exporting nodes and using features + diff to check whether they have changed (to revert or do any action on the feature), using dependency leads to false positives due to possible different ordering on disk and in memory generated feature.

The solution is to make sure the dependencies are always generated in the same order when listing them.

I attached a proposed patch which used this ordering : type > id > field_name
Tested OK on my dataset with sometimes same id on different fields (so dependency is added multiple time for different field names)