Current method for merging datasets does not retain variable attributes.

[IanTBlack]

Variable attributes are essential. OOIJH users may choose to view a dataset to get attributes such as units and processing level.

A possible solution is to retain the attributes in memory at the first instance of import_file and reassign them after merging.

[IanTBlack]

Resolved in commit c02bfca.

[IanTBlack]

This issue remains in the metbk module. This is due to renaming of variables.