Create README.md

Reduce includes

Fix missing instance object of bnw::args

Add parantheses around macro args

Modernize Code: nullptr, make_unique, typedef->using

Use new headers, const pointers and override

Use auto where the type is clear (casts...)

Use noreturn only for GNU

Fix signed/unsigned mismatch

Use format attribute only for GCC

Fix remaining warnings

Raise C standard to C11

Fix many warnings (sign covnersions)

Add noreturn and const to char*

Add format attribute