Changed the layout of export buttons as discussed with Jeff

Hello Jeff,
I implemented the changes you proposed (with a dropdown on the save button).

As you reverted the commit I didn't manage to create the proper pull request (only latets modifications appear, but not differences between yesterday's branch and your develop branch). 

You will probably need to pull from my github repository to properly merge the changes, and merge manually the files.
If you merge manually it's based on your develop branch from yesterday's before you fixed the combo max items.

Please test before pushing back updates: I am at home and don't have did have timeto setup kairosDB for testing with data, but I did not change the logic: only the UI.

Regards,
Loic