docs: fix a typo in plugins page.

docs: fix a typo in plugins page.
change 'chroma' to 'chrome'
test(client): add a unit test for buffering
feat: redirect client to "return_url" if specified

When capturing a browser, the url can specified a return url (as query param `return_url`) and Karma will redirect the client to that url after the test execution is done.
Merge pull request #726 from tychio/patch-1

docs: fix a typo in plugins page.
docs(migration): module.export/module.exports

Change code snippet to use module.exports rather than module.export, because that's what the runner expects, and previous sample code doesn't work from copy-paste.
Merge pull request #766 from psyked/patch-3

docs(migration): module.export/module.exports
fix: launcher kill method which was throwing an error if no callback was specified
bug introduced in https://github.com/karma-runner/karma/commit/8647266fd592fe245aaf2be964319d3026432e33

In server.js when singleRun = true, no callback is passed to when a browser complete to launcher.kill so if a browser is not yet connected but one has already finished the process throw an error.

TypeError: undefined is not a function
    at process._tickCallback (node.js:415:13)
chore(config): cli instructions

Updates reference from karma object to config object.
Merge pull request #781 from jeffjewiss/patch-1

chore(config): cli instructions
fix(static): Use full height for the iFrame.
Fix based on PR #714.
docs(config): Fix the browser/plugin list in the config file documentation.
chore: Add node dependency badges.
docs(config): fix a typo
style(config.tpl): add note about installation of launcher plugins
Merge pull request #776 from yhwh/fix-error

fix: launcher kill method which was throwing an error if no callback was...
fix(web-server): strip scheme, host and port

Absolute URI requests are striped to match files in middlewares.
AbsoluteURIs are use from proxies according to [Section
5.1.2](http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html)

PR to LearnBoost/socket.io#1304 is needed to fully resolve this issue
karma-runner/karma#705
fix(watcher): improve watching efficiency

This fix significantly improves watching performance. It tells chokidar to
ignore all paths that do not match any of the watched patterns.

Before we were only ignoring paths that match some of the excludes patterns.
That means that even files that didn't match any of the watched patterns were
still watched by chokidar and ignored on the level of `fileList`.

Note, this fix requires chokidar 0.7.0

Closes #616
feat(watcher): ignore initial "add" events

Initially all the patterns are scanned using glob. Then we start watching then
with chokidar. Chokidar now allows to ignore initial "add" event, which was
ignored by the fileList anyway.
fix(watcher): ignore double "add" events

On linux, `fs.watch` (which chokidar uses when `usePolling: false`)
fires "add" events twice. This change makes `fileList` to ignore the
second event.
feat(config): add usePolling config

This config option is forwarded to chokidar. When set to `true` (default value is `false`), chokidar uses `fs.watch` instead of stat polling.

This seems to be finally working well on linux, however it does not work on Mac.
See https://github.com/paulmillr/chokidar/issues/62

That's why I'm leaving it undocumented ;-)