Build: Update devDependencies & jsHint configuration

It's a good practice to list peerDependencies directly in package.json,
especially that current auto-installing behavior will go away in future
versions of npm: https://github.com/npm/npm/issues/5080

Also, jsHint plugin should search for proper .jshintrc files on its own;
current behavior integrated badly with IDEs in some cases.
Build: Increase disconnect tolerance in Karma config

So far, in case of a browser being disconnected from Karma we are getting
a failure. Since it happens quite often, especially for slower browsers,
increase the disconnect tolerance to 3 times.