Added rudimentary PUT action, that creates new projects.
Abstracted name of each data item away from its html representation (using "name" attribute).
DELETE action for projects implemented.
Dataset deletion implemented.
Using convenience function to formulate path to REST API.
Flattened the control structure by creating independent "refresh" functions for the three columns of data.
Added fading control for refresh; delete button for projects.
Project deletion works now.
Dataset deletion works.
Merge branch 'unnest' into tangelo-rest

Redid the application logic with a collection of "more atomic" functions, rather
than putting everything into a giant pyramid of inverted control.
Deselect the selected item if it's clicked again.
Confirmation dialogs pop up to confirm deletion; clicking context buttons don't cause highlight toggle.
Minor UI changes - non-"fading" dialog for adding new project, and added a comma to copy for dialog box.
Added file loading buttons.
Better loading button strategy.
Added infrastructure for selecting new dataset file.
Mechanism for adding new datasets added - need way to specify file types, etc.
Merge branch 'tangelo-rest'