howto-compile-linux: Update Lua module prereqs

List both for Debian Wheezy and Squeeze. Add a note about Lua 5.2 and
LuaSocket.

See also:
* http://lua-users.org/lists/lua-l/2012-09/msg00326.html

Signed-off-by: Toni Gundogdu <legatvs@gmail.com>