Include QtNetwork before using it

* Fixes compile errors on arch Linux
Fix test failures from warnings

* Some machines print warnings to stderr from plugins
* We can't silence these warnings and the tests fail
* Tests now look for a specific string instead of any output
Capybara spec_helper is in capybara/spec
Frame focus via Capybara::Element

Fixes #465.
Implement Node#all_text

The #text method in Capybara 2.1 differentiates between visible and
invisible text. This requires that Node implement #all_text.

To maintain backwards compatibility with Capybara 2.0, Node#text has
been aliased to #visible_text.
Implement Browser#title
Don't ignore hidden elements for click test spec
Use JSON.load to instantiate errors

As of JSON 1.7.7, JSON.parse no longer instantiates json_class as
specified in the source document. JSON.load retains the original
behavior.
Build against Ruby 2.0.0
Bump Sinatra to silence security warnings
Remove lingering references to Node#text
Implement Driver#find_css and Node#find_css
Remove duplication from Javascript error handling
Update appraisals for capybara 2.1
Add selenium-webdriver as development dependency

Capybara 2.1 will make selenium-webdriver optional.
Rename Find command to FindXpath
Remove return from JavascriptCommand finish
added support for double and right click