Implemented new distribution scheme.
Select is now purely C.
HTTP reimplemented seems faster dunno why.
LTN12 functions that coroutines fail gracefully.
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.
