*** (httputil) major rework, new caching implementation, unified request

***  (httputil) major rework, new caching implementation, unified request
     processing
+    (httputil) post support, partial request support, other features
-    (httputil) removed partial_body() and get_cached() [merged into get()]
*    (plugins/, utils) minimal changes to accomodate for the new http_utils
*    (utils, ircbot) moved utils initialization into utils.rb
*    (tube.rb) (partially) accomodate for upstream site layout changes