Improve error message if no framework was loaded.

Running karma on windows 8 throws the following error when trying to run in browser:

> IE 11.0.0 (Windows) ERROR
> You need to include some adapter that implements __karma__.start method!

Reproduce:
- clean node install on win8 (removed npmrc)
- npm install -g karma
- npm install -g karma-cli
- karma start -> does not throw error yet
- connect browser -> throws the aforementioned error
- karma run from another console -> throws again

Start by reproducing the Windows 8 sequence with global karma and karma-cli installs, then connect the browser and run karma from another console. Trace where the “include some adapter” error is produced; done means the failure reports a more useful message when no framework is loaded.

Written by the indexing model from the issue text.