Some compile time variables like the cflags and prefix have been moved to
the node_config.h.in, in the anticipation that they will be removed at
somepoint.

Added default values for many parameters, missing properties and methods,
and slight reorganization of the Child Process section.

Those variables have following defaults :
 - NODE_PREFIX is relative to the current path of the node_addon.py file
   It is used as the base path of node include files.
 - NODE_PATH is ~/.node_libraries
   It's where modules are installed when calling `node-waf install`
   Note .js files must be explicitely installed by the module's wscript.

Usage :
NODE_PREFIX=/usr/local NODE_PATH=~/.node_libraries node-waf configure

Added consistency to the representation of optional parameters and separated
out multiple functions that were in a single heading.

- Add docs for 'fd' events, Server.listenFD(), Stream.write(...[, fd])
  and http.Client 'upgrade' event.

This reverts commit 8f8dcf8e.

Done by not evaluating the code in the first tick.

This breaks one test in test-error-reporting.js but I believe this to be a
V8 error and I have reported it in
http://code.google.com/p/v8/issues/detail?id=764

Remove strange code artifact