Merge pull request #54 from charlotte-raillere/london_hackaton

Add missing import for clinical export with filter
Changed pop-up warning on Data Grid to reflect the fact that Summary Statistics needs to be run first.
Additional log.debug statements
Add transmart-rest-api to plugins
Fixed Filter disappeared issues when we use Advance workflow
Merge pull request #55 from sh107/london_hackaton

Fixed Filter disappeared issues when we use Advance workflow
Add function to remove values in metadata