Major Functionality Update and Bugfixes

Going back on my word, I've returned to this project again. It felt incomplete if it didn't have the functionality to directly import brushes from files.

Technical talk incoming:

I was initially put off from implementing direct from file importing because I had no idea where to start creating Brush2.ini entries from scratch. But after looking at the Medibang Brush2.ini and in app import behavior I started noticing patterns.

1. All entries start with essentially the same lines up until the file is specified, then the rest is usually going to 'options' except if it's a pen, airbrush, eraser, or smudge

2. All entries with associated files are either script or bitmap types

3. If you delete the options sections in an entry for a script type brush, Medibang will repopulate them during run time

4. Bitmap type brushes have a maximum of  7 options and there is no way to distinguish a bitmap watercolor, scatter, etc from the file alone

Using this information, I implemented a very basic direct from file brush import function where I create a new Brush2.ini from scratch using 'default' values for all files and then piggy back off of previously developed systems for copying files, etc. As a result, the brushes imported will not have any author intended presets and the user will have to tweak the sliders in Medibang. 

In addition to the main feature, I also improved the accuracy for importing FA brushes. Turns out including the extra parameters that don't have analogs in Medibang causes Medibang to freak out and default the brush type to a very basic brush.

Additional QOL features are:

- Inputting the wrong config path in the initial window will no longer crash the application

- Added some preemptive prevention against file name conflicts by implementing auto renaming duplicates