Update the other links on PhantomJS builds [ci skip]
#395 Add better error message for wrong xpath

If someone fill wrong selector in `find` method this poor description will be shown:
"There was an error inside the PhantomJS portion of Poltergeist.
This is probably a bug, so please report it.
Error: INVALID_EXPRESSION_ERR: DOM XPath Exception 51"
Now we raise `InvalidSelector` in consistency with selenium.
Fix #398 remember server port rather than ask server for its port each time
Don't forget to call quit on custom driver
Fix #263 add `basic_authorize` method
Fix #263 HTTP Basic Authentication
* Use strip on Authorize header otherwise it forms bad request
* Combine both methods settings and manually set header
Add CHANGELOG entry
Add missed change log and readme entries [ci skip]
Cherry-pick mouse events at from michiels