New feature added: one can specify additional transparency of watermark image

I was missing one feature.

Let's imagine that I have the following image:

I want to add a watermark to it:

Note that the watermark is white graphics in transparent background. Using already existing tool I can easily obtain the following image:

In my humble opinion, it's not as nice as I'd like it to be. Hence I decided to slightly modify watermark plugin. I added possibility to add transparency to the watermark graphics.

Batch Queue Manager with watermark plugin by default looks like:

As one can see, there is additional checkbox which is unchecked by default. I can enable it, and opacity value is set to 100%:

After running this batch I obtain the very same image:

However, when I decrease opacity to 75%:

I obtain the following image:

I can repeat it for any opacity value I'd like:

For 50%:

And 25%:

One can decide which one is the best.

According to my observations, there is no one best suitable opacity level for all photos. Hence such a feature will simplify my work.