Add encode and decode functions for strings solving issue #13
Add encode and decode functions for strings solving
issue #13

Functions <code>decodeByteArrayToString</code> and
<code>encodeStringToByteArray</code> added to the global
context WyJS. Functions work in to solve issue #13 of
integer array of UTF-8 bytes and the strings in
JavaScript not supporting them. They work properly for
printable UTF characters. Tests using them are still to
be created.

Decode function uses <code>decodeURIComponent()</code>
standard JS function to decode the integer array. Encode
function simply uses charCodeAt() standard string
function to encode the characters and push them to an
array of integers.

Other solutions for encoding were found, more ocmplex
but they don't seem to be relevant to the Runtime at
this stage.

Whiley/Whiley2JavaScript,Whiley/Whiley2JavaScript