V0.8.0

@christian-bromann @camme What do you think?

I rebased the 0.7.14 branch and we should work on 0.8 now.

I refactored a little the test so that we do not require a test runner and we can keep using the standard mocha command line.

We should not merge 0.8 right now, here's what's we can do/did:

- [x] remove the php dependency for testing
- [x] allow easy local testing
- [x] remove the need for chai/expect, use simple assert
- [x] explain how to local [test easily](https://github.com/camme/webdriverjs/blob/a4de248dba49c83f1271fae3638bfc8a2d3b3d7e/README.md#testing)
- [x] do not use a specific runner, just use simple mocha and a [require bootstrap.js](https://github.com/camme/webdriverjs/blob/ce8b010be5e29ac9ca1eb02b23446127666e7f44/test/mocha.opts#L4)
- [ ] travis ci build

  To simplify things for now and to allow easy local testing.

Which is the first thing we should always get from a project so that anyone can participate in it.

I had to remove some travis-ci specific code, right now I don't know if it will work.

I don't know how to simulate and launch a travis build either.

  We should use a travis.sh build script that will run. Something like:
  ```sh
  BROWSER=chrome VERSION=28 tags= build=.. npm test
  ```
- [x] `.pause(1)`. It seems @christian-bromann you stumbled on what I call the `fucking pause(1) bug`. There's a bug in the chain API or there's a feature we do not understand that prevents us from removing all pauses. Why would we need to [pause(1)](https://github.com/camme/webdriverjs/blob/ce8b010be5e29ac9ca1eb02b23446127666e7f44/test/spec/windowHandle.js#L97) in some circutance otherwise the chain api stops? I don't know but it's a nasty bug.
- [x] The promises test is broken, see my comment in it around the [setTimeout](https://github.com/camme/webdriverjs/blob/ce8b010be5e29ac9ca1eb02b23446127666e7f44/test/spec/promises.js#L47), there's no way the chain API will ever know how to deal with such circumstances like an inside setTimeout. Should we support it? I think not.
- [ ] tests for not tested protocol methods
- [ ] make cookie test work
- [ ] maximize window features
- [ ] host test web site/ on github.com so that everyone can update it
- [ ] do not include the tab word, only deal with window_handles
- [x] switch to an external module for chaining

Any other feature you want to be included in 0.8.