Loader now adds a layer instead of opening a file in Photoshop

This branch implements the Add To Layer action for the loader. It supports both images and PSDs.
The 3 main tasks were:
- Renaming the Open File action to Add To Layer.
- Adding a check to make sure there is a current document.
- Using the Place action to create the layer.
Oh definitely, it totally beats googling. The rosetta stone link would be nice to include as well. No more cryptic 4 letter words for everything. I've looked at Adobe's scripting reference and even tough they list the "Plc " action, it is not documented, nor are any of it's parameters. I'm new to Photoshop, but it really feels like a blackbox. You have to experiment.