getting rid of forceCompletion attribute responsible for buggy autocomplete. fixes issue 7928
Preventing driver hangs caused by TypeError: can't access dead object, when a document is removed at the moment we execute some script. Instead of hanging it should throw an exception. Fixes issue 7934
Removing unused HasBrowserConnection driver extension

This is related to this issue:
https://code.google.com/p/selenium/issues/detail?id=7315

HasBrowserConnection is a driver extension that is only an option for the Android driver. The
Selendroid JSON Wire implementation doesn't support the browser_connection method anymore,
so all code related to this driver extension can be removed from the Ruby bindings.

Here you can verify that the browser_connection method is not available anymore:
https://github.com/selendroid/selendroid/wiki/JSON-Wire-Protocol:-Supported-Methods
https://github.com/selendroid/selendroid/blob/master/selendroid-server/src/main/java/io/selendroid/server/AndroidServlet.java
https://github.com/selendroid/selendroid/blob/master/selendroid-standalone/src/main/java/io/selendroid/server/SelendroidServlet.java