Currently this gem uses an outdated version of 'batman.js' (0.14.1).
A newer version of batman.js (0.16.0) adds a filter named `delimitNumber`, which
formats long numbers for better readability ('1000000' becomes '1,000,000'), and
would be very useful for manipulating data used by the `Number` widget.
Since upgrading batman.js to 0.16.0 entirely causes breaking changes to the
entire app, this commit simply backports the required `delimitNumber` function
to version 0.14.1. Now the app can benefit from this new filter functionality
without breaking everything else.
I have no plans to open a PR on the original `dashing` gem repo because
batman.js itself is no longer actively maintained , so the PR will not
be accepted. In fact, there is already an open discussion  on the `dashing`
gem's repo about moving to a different JS plugin in order to replace the
functionality batman.js currently provides, but with a tool that is actively