Updated some of the callbacks in callback.lua.

Update get.lua to use the new callbacks.
The old "code" module is now the "mime" module.
Updated all modules that depended on it.
Updated url.lua to use the new namespace scheme, and moved the
    escape and unescape functions that used to be in the code.lua module
    to it, since these are specific to urls.
Updated the callback entries in the manual.

src/http.lua

@@ -421,7 +421,7 @@ end
 -----------------------------------------------------------------------------
 local function authorize(reqt, parsed, respt)
     reqt.headers["authorization"] = "Basic " .. 
-        (socket.code.b64(parsed.user .. ":" .. parsed.password))
+        (socket.mime.b64(parsed.user .. ":" .. parsed.password))
     local autht = {
         nredirects = reqt.nredirects,
         method = reqt.method,
@@ -429,8 +429,8 @@ local function authorize(reqt, parsed, respt)
         body_cb = reqt.body_cb,
         headers = reqt.headers,
         timeout = reqt.timeout,
-        host = reqt.host,
-        port = reqt.port
+        proxyhost = reqt.proxyhost,
+        proxyport = reqt.proxyport
     }
     return request_cb(autht, respt)
 end
@@ -471,8 +471,8 @@ local function redirect(reqt, respt)
         body_cb = reqt.body_cb,
         headers = reqt.headers,
         timeout = reqt.timeout,
-        host = reqt.host,
-        port = reqt.port
+        proxyhost = reqt.proxyhost,
+        proxyport = reqt.proxyport
     }
     respt = request_cb(redirt, respt)
     -- we pass the location header as a clue we tried to redirect
@@ -482,8 +482,8 @@ end
 
 -----------------------------------------------------------------------------
 -- Computes the request URI from the parsed request URL
--- If host and port are given in the request table, we use he
--- absoluteURI format. Otherwise, we use the abs_path format.
+-- If we are using a proxy, we use the absoluteURI format. 
+-- Otherwise, we use the abs_path format.
 -- Input
 --   parsed: parsed URL
 -- Returns
@@ -491,7 +491,7 @@ end
 -----------------------------------------------------------------------------
 local function request_uri(reqt, parsed)
     local url
-    if not reqt.host and not reqt.port then
+    if not reqt.proxyhost and not reqt.proxyport then
         url = { 
            path = parsed.path, 
            params = parsed.params, 
@@ -543,6 +543,7 @@ end
 --     error: error message, or nil if successfull
 -----------------------------------------------------------------------------
 function request_cb(reqt, respt)
+    local sock, ret
     local parsed = socket.url.parse(reqt.url, {
         host = "",
         port = PORT, 
@@ -561,14 +562,14 @@ function request_cb(reqt, respt)
     -- fill default headers
     reqt.headers = fill_headers(reqt.headers, parsed)
     -- try to connect to server
-    local sock
     sock, respt.error = socket.tcp()
     if not sock then return respt end
     -- set connection timeout so that we do not hang forever
     sock:settimeout(reqt.timeout or TIMEOUT)
-    local ret
-    ret, respt.error = sock:connect(reqt.host or parsed.host, 
-        reqt.port or parsed.port)
+    ret, respt.error = sock:connect(
+        reqt.proxyhost or PROXYHOST or parsed.host, 
+        reqt.proxyport or PROXYPORT or parsed.port
+    )
     if not ret then 
         sock:close()
         return respt