Added initial port of original OSX project.

- This is a copy of the [OSX](https://github.com/bkuhlmann/osx) project
  originally released on 2012-03-31. The OSX project has been
  deprecated. All future development and support will take place with
  this project instead.
- This project uses the *macOS* name in order to better match the
  updated branding and terminology used by Apple.

lib/reinstallers.sh

@@ -0,0 +1,18 @@
+#! /bin/bash
+
+# DESCRIPTION
+# Defines reinstall functions.
+
+# Reinstall application.
+reinstall_application() {
+  uninstall_application
+  scripts/applications.sh
+}
+export -f reinstall_application
+
+# Reinstall extension.
+reinstall_extension() {
+  uninstall_extension
+  scripts/extensions.sh
+}
+export -f reinstall_extension