General Fixes

* Attempts to resolve #664 I originally was confused by Studio, ENIGMA's original mouse_x and y handling was perfectly fine, I was testing a Studio game that would glitch with the view when the mouse moved outside of the window, this is because GM8.1 allowed that to occur, Studio on the other hand does not update the mouse outside the window, which appears to happen in their window manager because the mouse position when moved into the negative range will freeze sometimes at numbers larger than 0. I have restored the original code, updated the comments, and made window_views* functions work properly now. Now however, we do make a slight modification that makes the mouse handling work better than both Studio and GM8.1 combined, we use the current view instead of doing a bounds check, this allows the constants to work properly with overlapped views while being backwards compatible and working for split screen views and allowing the mouse to also go outside the window.
* Implements debug scoping, so when show_error is called in debug mode it will tell you the exact event of the exact object, or the script name that it occurred in. It utilizes a stack and will show the entire queue.
* Fixes INI functions and registry functions, a few of them had the same issue as environment_get_variable which was fixed in #703 where they were returning extra characters at the end because of the way the character buffer was handled, somebody tried to do it on std::string which may have been compiler dependent. Also implements the two missing INI functions for deleting a section or key, according to the Microsoft documentation, you just pass NULL
http://msdn.microsoft.com/en-us/library/windows/desktop/ms725501%28v=vs.85%29.aspx
* Fixes Studio Box2D extension reported broken in #708, Josh renamed the angular conversion macros and never tested anything.
* Fixes instance_position reported in #607, in GM8.1 and Studio instances are allowed to call the function on themselves.
* Implements outside view and boundary view events from #431