Add support for Firefox browser width and height.

Copied PhantomJS code to set webdriver width and height over to
FirefoxDriverFactory.
Merge branch 'feature/firefox-size' of https://github.com/markkimsal/selenese-runner-java into markkimsal-feature/firefox-size
add support initial width and height for other browsers. (excluding mobile)
stop save password prompt on Safari.
fix JavaDoc.