Version 0.2: Leaner and meaner

• Moved to simpler syntax, where Option pointers are returned and operated on
• Removed make_ style options
• Simplified Validators, now only requires ->check(function)
• Removed Combiners
• Fixed pointers to Options, stored in unique_ptr now
• Added Option_p and App_p, mostly for internal use
• Startup sequence, including help flag, can be modified by subclasses