gi-gtkosxapplication-2.0.16: ChangeLog.md

### 2.0.16

+ Update stack version to 12.10

+ Change the description of the package to mention gtk-mac-integration, to improve discoverability.

### 2.0.15

+ Remove enable-overloading flags, and use instead explicit CPP checks for 'haskell-gi-overloading-1.0', see [how to disable overloading](https://github.com/haskell-gi/haskell-gi/wiki/Overloading\#disabling-overloading).