Several large improvements

[TacoTheDank]

Apologies, I didn't fork this expecting to make a pull request this big. I came here to only fix a couple things and it grew into this as I found more and more stuff to improve.

Here are the changes to note:

• Added Java 8 support (lambdas, etc.).
• Some code cleanup.
• Adjusted codestyle to an .editorconfig (there were tabs AND spaces being used, oh the horror!).
• Converted drawables to vectors.
• Changed the color of the actionbar to be less bright and blinding.
• Created an adaptive icon using paint.net and one of the old icons (Could be made better if I had the original transparent PNG; I am willing to remake them if you have it).
• Optimized PNGs using https://ezgif.com/optipng.
• Disabled the actionbar color changing (this is because if you use the extract color on a blank canvas, everything turns white and you can't see anything anymore (this will have to be fixed by providing something else to show the color (like maybe a circle dot to the right of "Acrylic Paint" that's not a part of the menu that updates with each color chosen))).
• Rearranged the settings to make more sense (menu-wise).
• Screenshots now export in ARGB_8888 (32-bit color) instead of RGB_565 (16-bit color).
• Added a permission check for writing to external storage (required for Marshmallow and above).
• Added options for clearing both only the background and both the background and foreground at the same time.
• Created submenus for deletion options and drawing effects (bold, blur, smudge), so the settings list isn't so cluttered.
• Fixed missing translations using the powerful DeepL translation service.

Yeah... that's a lot.

Here's an APK for your testing. You're gonna want to see this. app-release.zip

Thanks. :)

[valerio-bozzolan]

Wow! Such big.

First of all, thank you for your work my friend.

I will review your changes ASAP.

[TacoTheDank]

Thanks!