Alpha v0.4.0

This was meant to be a small update before I would start working on getting iterator (batch upscaling) support implemented, but I ended up doing a lot more. Hopefully these changes improve the experience for people!

Dependency Updates:

• NCNN has a new update that should increase the speed of upscaling, but your mileage may vary. You can update this via the dependency manager!

Features:

• Added new outputs to certain nodes to file names to be connected to text inputs.
• Added a new "Text Append" node for concatenating multiple text outputs together with a separator string. This can be used for appending the model name to the image name.
• Added a new "Add Caption" node to apply a caption to an image. This is useful for captioning comparison images.
• Added Gaussian Blur and Sharpen nodes.
• Added Overlay Images node. (thanks @theflyingzamboni)
• Changed the validity icon to be red when a node is invalid, so it is more apparent what nodes are not correct.
• Changed the validity icon to have a white checkmark when a node is valid, so it is easier to see the checkmark.
• Changed a small thing about how I handle NCNN upscaling that should improve performance slightly.
• Added a small number input to the side of the slider input. Both control the same value, making it easier to input specific numbers if you need to.
• Images with transparency will now use the "Background Difference" transparency hack from my ESRGAN fork when upscaling 4-channel images with 3-channel models (most models). To get the "Separate" mode functionality, you can still split the image like what was required before. If you're curious how this works, it basically upscales two versions of the image, one with a black background and one with a white background, and then makes transparency off of the difference between the results, which (in an ideal scenario) will just be the background transparency. This isn't perfect though, and it's why I didn't initially want to put it in, but it should work well enough in most cases. If you do not want to use this, then make sure to upscale just the RGB by splitting the transparency off using the new nodes mentioned below. Also, differing from the implementation in my fork, it will ignore single-color transparency.
• Along with the above, two new nodes have been added to aid in splitting and merging transparency specifically, since the old way was a bit convoluted (having to use a split and then a merge immediately after)
• Added an update check on startup that will let you know if a new version has been released.
• Added the ability to automatically submit a GitHub issue if chaiNNer crashes unexpectedly.

Bug Fixes:

• Fixed text inputs not getting loaded properly from files
• Fixed the "model save" node not having the right kind of model input
• Fixed node validity treating certain empty inputs as valid
• Fixed an error that could happen if you load a chain with certain invalid nodes (for example if you don't have some of the dependencies installed)