Recursively merge field views data

field_views_data() merges in all field data, but not recursively.
Image module's views implementation uses hook_field_views_data_views_data_alter() to add reverse relationships, which is fine because it is operating on a table it doesn't define.

Field Collection's views implementation uses image as a guideline, but the alter is operating on our own table, so this could theoretically be done in the original hook itself, not the alter, which would let other modules more reliably alter it, without worrying about weights.

The current field_collection_field_views_data() adds information about each field to $data, while the alter adds info to $data['field_collection_item']. If the two functions are combined, the value of $data['field_collection_item'] is overwritten by each call to the alter.

Because of the nature of the data being provided, I don't believe the change to array_merge_recursive will cause any problems. Patch forthcoming.