misc: add `function` keyword
misc: converts a number between different numbering systems: bin2oct, bin2dec, bin2hex, oct2bin, oct2dec, oct2hex, dec2bin, dec2oct, dec2hex, hex2bin, hex2oct, hex2dec
misc: binary, octal, decimal and hex predicates
misc: baseconvert: ability to use more than one number to convert
misc: use predicates in `bin2oct`, `bin2dec`, `bin2hex`, `oct2bin`, `oct2dec`, `oct2hex`, `dec2bin`, `dec2bin`, `dec2oct`, `dec2hex`, `hex2bin`, `hex2oct`, and `hex2dec` functions