Add to jquery.client's qunit tests by actually testing the test() function against...

Add to jquery.client's qunit tests by actually testing the test() function against the sample user-agents.

Also changed from hardcoded constant of how many user-agents to test to counting them so it won't get out of sync.

Added Firefox 10 and IE 10 sample user-agent strings in to make sure they test correctly.
They *do* test correctly *if and only if* you use raw numbers for a major-version test (eg > 7). If you tried > "7.0" you would find it fails on the version 10 browsers.