feat #587 semi-transparency on test iframe

If the iframe test fails and the iframe is not disposed, it's hard to
see if there was some error or no (on beta.html).

In general it's good to be able to see the status of the current test.

Close #587.
fix #591 failing template tests due to wrong usage of Syn

After updating Syn in 104a7f2cddcabfe50919ce546518edb119ef24ff, the tests (fixed in this commit)
were failing on IE7 because they were using Syn incorrectly, trying to click on an invisible
element.