Replace core language HexStrings with library entity

[Daniel Murphy via Digitalmars-d]

"Nick Treleaven"  wrote in message news:me6jo4$ca$1 at digitalmars.com...

> 0b1010 binary literals (even though C++11 supports them)
> 0xABCD hex literals (but useful for porting C)

You can take them when you pry them from my cold, dead hands.  These are 
1000x times more useful than octal and deserve to be built in.