Settings

added the `settings` api, plus implemented the setting for xpath compression.
added docs and tests

will squash once approved of course,

Oh, also had to add to wd.js to get the tests working. If we are ok with my implementation I'll push there. In the meantime you can clone [my fork of wd.js](https://github.com/jonahss/wd).

And then I'm going to go and update the rest of the clients....

(of course I'll squash, once we're through here ;)
I think there's a misunderstanding about what `compression` does. There needs to be two changes to the server:

- on server boot, if the cap is set then discard not important views must be enabled. This is similar to how the JSON is loaded for strings.xml
- A new command must be added to enable toggling the compression. The existing commands such as Find.java should not have any changes other than removing any calls to discard important views.