More markup around JB's container for correct height calculation.

JB's height calculation was slightly messed up after we moved the toolbar
around recently.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Add button to toggle track labels.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Make search track deletable

Any track can now be made deletable by adding {deletable: true} to
track config.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>