Patches for error.h and error.c

Hi, Attached is a patch for error.h/.c. Some comments: The WinHugs specific bit now uses int instead of INT, so its not dependant on windows.h The error message on compile time errors now puts out a hyperlink, this is #if'd so shouldn't change non WinHugs. This allows WinHugs users to click when an error occurs and be brought to that location in their editor. Instead of proding MessageBox(hWnd), I have defined InfoBox and ErrorBox which WinHugs does something sensible with. The header file uses cleaner interaction with WinHugs, instead of poking the magic hWnd.. Thanks Neil