added a possibility to configure the selenium webdriver timeout, and rep...

...eated the json load try in selenium.

The given default timeout for selenium (30sec) may not be enough to run a big suite in ci mode. I added a env configuration possibility to increase the timeout. Also, in our environment,  the ci task failed with "uninitialized constant Jasmine::SeleniumDriver::JSON" despite the prerequisite in the rakefile. I repeated the require in the given class and added specs.