REMINDER: macOS builds to fix non-updating cached code on compile

[alanspencer]

There is a issue with macOS/Xcode builds where the previous build folder still exsits. QT/Xcode appear to use cached code when re-building, and at times this ignores changes to certain files. For example, the global version.pri, and image resources such as icons.

The solution to fix this issue is to manaully delete the build folders and then compile.

This is especially important when releasing a new version of SPIERS inorder to propagate the new version number to the program builds. Result of not doing this/checking version number before release is a program that gets stuck in an update loop!