Enhancement - Hooks

- Added many more format hooks.
- Added unit tests for all added hooks.
- Added unit tests for format-countdown and format-countdown_compact.

src/command.cpp

@@ -1646,7 +1646,13 @@ void handleShell ()
 
     do
     {
-      std::cout << context.config.get ("shell.prompt") << " ";
+      std::string prompt = context.config.get ("shell.prompt");
+      if (context.hooks.trigger ("pre-shell-prompt"))
+      {
+        context.hooks.trigger ("format-prompt", "prompt", prompt);
+        std::cout << prompt << " ";
+      }
+      context.hooks.trigger ("post-shell-prompt");
 
       command = "";
       std::getline (std::cin, command);