Allow hexadecimal input

I think it would be useful, especially with bitwise operations, to allow hexadecimal input and output.

Basically, any number prepended with 0x would be parsed as hexadecimal. All others would be decimal. If there is any input that is hexadecimal, then the output should be hexadecimal, and prepended with 0x.

Examples: 0x400 * 2 = 0x800 0x123 | 0x321 = 0x323 200 * 0x1 = 0xC8