_testCaptureImage is now captureImage. [1660]

ISL formatter objects will be ignored if height, width, or bgtransparent
parameters have been used. A warning will be printed out if the user
attempted to use both the parameters as well as the formatting objects
in a single call to captureImage.
Potential fix for labels showing up twice. [1660]

I'll probably be poking at this a little more, but I believe it's
suitable for testing as-is.