module to encode/decode to/from application/x-www-form-urlencoded encoding

 URL::Encode provides functions to encode and decode strings into and from the
 application/x-www-form-urlencoded encoding.
 .
 The application/x-www-form-urlencoded format encodes an ordered data set of
 pairs consisting of a name and a value, with pairs separated by ampersand or
 semicolon, and names and values separated by the equal sign. Space characters
 are replaced with a plus sign, and any character not in the unreserved
 character set is encoded using the percent-encoding scheme also used for
 resource identifiers. A percent-encoded octet is encoded as a character
 triplet, consisting of the percent character "%" followed by the two
 hexadecimal digits representing that octet's numeric value.
 .
 The unreserved character set includes the uppercase and lowercase letters,
 decimal digits, hyphen, period, underscore, and tilde.