Integrity Checking

One of the most important non-functional features of a library like this is making sure that you, the developer, don't have to test the input with various garbage to make sure you've implemented the library correctly. In that spirit, I've done my best to sanity check the Attributes you place on your options class when the parser is initialized (before any arguments are passed to it). You shouldn't have to wait until a user passes the wrong arguments in to discover that you've defined a duplicate argument short name or that the constant values you're storing aren't actually convertible to the property type.