build: added script for creating MacOSX app bundle

This change makes it possible to create a MacOSX app bundle of either Debug or Release builds:
* The script setup/MacOSX/bundle_install.sh is configured by cmake to be placed in the apps Debug and Release folders.
* Execution of bundle_install.sh creates the bundle file structure and copies binaries, libs, frameworks and resources
into it.
* The script uses install_name_tool to reconfigure the dynamic library paths and framework paths of the binary, so they
won't point to the system libraries, but to the locations in the bundle instead.
* An Info.plist file is also configured by cmake and placed in the bundle by the script. Note: It is named
bundle_info.plist in the Debug and Release folders after configuration so the start of the binary during developement
does not use it.
* When opening the bundle it is assured via setup() in src/app/platform_includes/includesMac.h that the working
directory of the binary is set to .app/Contents/Resources so the paths to the data files are evaluated correctly.

fortune cookie message = Dein Einsatz wird in Kürze belohnt werden.

src/app/CMakeLists.txt

@@ -1,6 +1,10 @@
 add_files(
 	APP_FILES
 
+	platform_includes/includesDefault.h
+	platform_includes/includesMac.h
+	platform_includes/includesWindows.h
+
 	qt/element/QtCodeFile.cpp
 	qt/element/QtCodeFile.h
 	qt/element/QtButton.cpp
@@ -39,6 +43,5 @@ add_files(
 	qt/QtWidgetWrapper.cpp
 	qt/QtWidgetWrapper.h
 
-	includesWindows.h
 	main.cpp
 )