No longer redirecting console output for Firefox in .NET bindings.

This information was largely unused by anyone, and the implementation
had a chance to produce deadlocks when reading from the console output
stream for stdout and stderr. Hopefully, this will help prevent some of
the problems with issue #3719.
Fixing XML documentation comment warnings
Fixing missed redirection of stdout and stderr for .NET Firefox.
fixed for current developing machine
Make the RemoteWebDriver implement TakesScreenshot.

There's only one driver that doesn't implement the interface (the HtmUnitDriver)
and this is the most common cause for using the Augmenter, which isn't very
discoverable.
Remove unnecessary implements statements. No logical changes.
On behalf of TommyBeadle: Fixing exception handling when building an inverted predicate. Fixes issue 2397
Add ability to send --silent flag to chromedriver

See https://code.google.com/p/chromedriver/issues/detail?id=116

Signed-off-by: Andreas Tolfsen <ato@mozilla.com>
Merge branch 'master' of https://github.com/SeleniumHQ/selenium

Conflicts:
	dotnet/src/webdriver/Chrome/ChromeOptions.cs
bugfix to use Guid.NewGuid("N") and not Random to generate the random temp dir so it works also with different processes