Remove unnecessary dependency on bouncycastle.
When Firefox is configured to accept all SSL certs (which is the default
behavior), we need to set a time offset to prevent Firefox from using
HSTS (HTTP Strict Transport Security). If we don't do this, Firefox will
pre-fetch the certs for sites that should always be accessed over HTTPS
and allows Firefox to catch man-in-the-middle attacks. While this is
A Good Thing for users, it prevents WebDriver from accepting self-signed
certs for these domains (e.g. when they are accessed through a HTTPS
proxy).
Add ability to save an abitrary base64 string as a screenshot from a
WebDriverJS test running in a browser.
Loosen input type to webdriver.stacktrace.getStack_ to account
for an rare condition in FF 28+ where the Error() constructor
returns undefined (not sure what causes it, just know it happens)
* Remove deprecated functions on webdriver.promise.Promise class
* Use templates with webdriver.promise.Promise to improve types
  documentation.