Change JB's Browse.getStore's semantics.

getStore now executes code after 'loadConfig' milestone. Additionally, we
ensure only one instance of a store is ever created.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
curate: Enable 'Done' button only if there's a gene model in edit track.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Ensure thanks modal can't be dismissed on escape key or random click.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>