Improve cmake and GUI (#13)

+ Packaging and CI for Windows, Mac, Linux
+ Debian package, NSIS Windows installer, OSX appbundle
+ Example application using libqtk
+ Component installation for `qtk`, `libqtk`, or `collection` with cmake

resources/icons/osx/README.md

@@ -0,0 +1,13 @@
+
+```bash
+sudo apt install icnsutils
+```
+
+```bash
+convert icon.png -resize 32x32 kilroy_32.png
+convert icon.png -resize 16x16 kilroy_16.png
+convert icon.png -resize 48x48 kilroy_48.png
+convert icon.png -resize 128x128 kilroy_128.png
+convert icon.png -resize 256x256 kilroy_256.png
+png2icns png2icns kilroy.icns kilroy_*.png
+```