Lift JS tests from JBrowse.

Using Jasmine 2.x. Thus some test files from JB had to be modified to
use `done` instead of `runs`, `waits`, and `waitsFor`. Additionally,
some tests used data from sample_data/. I copied relevant files from
sample_data/ to tests/data instead and modified corresponding tests.

To run tests:
    $ rake test:js
    now open localhost:9293/tests/js/index.html in browser

NOTE: It seems that RemoteBinaryFile.spec.js fails sometimes.

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