Data conversion related code functions

[Juan Facorro]

• binary - "Returns a string representing the binary value of an int, char or byte"
• hex - "Converts a byte, char, int, or color to a String containing the equivalent hexadecimal notation"
• unhex - "Converts a String representation of a hexadecimal number to its equivalent integer value"
• unbinary - "Unpack a binary string to an integer"