Ruby: Use base64 encoding for  :pack_simple_arrays option (to_simple_value)

Uses base64 encoded strings as return value for to_simple_value, in case :pack_simple_arrays option is used.

Base64.strict_encode64 is available from ruby 1.9.2, it is needed, bacause Base64.encode64 fills the String with additional newlines at teh end or after 40 chars (default in http headers, but not wanted here).
Steffen. I really don't have time for this. The whole binary encoding method is there to ease encoding a huge array and you are complaining for 7 BYTES FOR HEAVENS SAKE. The pack/unpack implementations are common to both Ruby and Perl, and other implementations float around for other major languages out there (Python and Javascript for once). So, no, you don't have to look into the pack code because others do it already for you.