karma - Allow execution with debug_mode=1. Hide jsonFormatter.

karma - Allow execution with debug_mode=1. Hide jsonFormatter.

Before
------

If you enable `debug_mode=1` and run `karma`, it produces a large number of failures:

```
PhantomJS 2.1.1 (Mac OS 0.0.0): Executed 81 of 81 (55 FAILED) (2.686 secs / 2.387 secs)
```

After
-----

If you enable `debug_mode=1` and run `karma`, it passes:

```
PhantomJS 2.1.1 (Mac OS 0.0.0): Executed 81 of 81 SUCCESS (7.232 secs / 6.95 secs)
```

Comments
--------

The `jsonFormatter` plugin is a DX nicety; when browsing a page with `?angularDebug=1` and with `debug_mode=1`, it will load extra
files so that `<crm-ui-debug>` panels look pretty. But ordinarily, loading these files is extraneous.