calc - Use the registry to store the configuration options

Right now, the calculator program that comes with ReactOS uses functions like GetProfileString()/SetProfileString() to set/read the configuration options. Unfortunately, these functions are provided as backwards compatibility for 16-bit applications as stated on MSDN pages for either functions.

CHANGELOG:

• Instead of using the outdated way of storing configuration data onto win.ini, which is used for 16-bit applications, use the Registry instead. If the compiler's target version of Windows is 2000 or later (#if _WIN32_WINNT >= 0x0500), then use the new Registry method. Otherwise, use the old method that saves/loads the configuration data to/from win.ini.
• Based on the registry value 'layout', set the checked state of the 'View->Group Digits' menu item based on what's in the registry when starting the program up.
• When trying to load the configuration settings for the calculator, if the values either cannot be found, or returns an error in some way, just use default values instead.
• Set the default layout of the calculator to Standard as it is the default layout mode in XP/2003.
• Minor spelling and capitalization improvements in whatsnew.txt