Important changes to the "Debug" build scheme.

Added new target, "Textual (No Addons)" which the Debug scheme now builds. This target is designed to allow quicker debugging of code. Instead of erasing build files each compile like "Standard Release," the Debug build now retains. It also does not build the frameworks or extensions anymore. Only the actual Textual application is built and only changed files are built so building code and debugging is almost instant.