'Set Selenium Speed' doesn't work after browser is closed #93

I'm having an issue with Set Selenium Speed when running multiple tests. In the failing scenario I have to 2 robot test suites that are running. In the first test suite, I open the browser, run some tests then close the browser. In the second test suite, I open the browser, try to 'set selenium timeout', run some tests and then close the browser. However, the set selenium speed in the second test is failing. I believe that robot selenium2 is trying to 'set selenium timeout' on the closed browser which is still in the browser cache.

I believe the following update is needed to resolve this issue:
File: _browsermanagement.py
Method: set_selenium_timeout
Original Code: for browser in self._cache.browsers:
Original Code: for browser in self._cache.get_open_browsers:

As a workaround, I'm setting the timeout while importing the selenium2 test library. Setting the timeout this way resolves my issue, but it also means that I can't set the timeout dynamically. (Haven't needed to do that yet luckily) Also, I believe a 'Close All Browsers' would clear the browser cache completely and would resolve this issue.

If I get a chance, I'll try to create an acceptance test to reproduce this issue and attach it to this issue. (I'm new to python, so it may take some time to put together a test to reproduce this.)