Waf 1.9
-------

* Reduce the key size in bld.task_sigs
* Provide a more efficient ConfigSet implementation
* Remove the split functions from Utils
* Ensure _cache.py are valid python files
* Include the tool 'nobuild' by default
* cflags in the beginning / cppflags at the end
* remove qt4 from the default modules, rework qt5
* remove the command called "update"

Waf 1.8.x
---------

Can be useful:

def bld_command(*k):
	fun = k[0]
	name = fun.__name__
	from waflib.Build import BuildContext
	class tmp(BuildContext):
		cmd = name
		fun = name
	return fun

@bld_command
def foo(ctx):
	print ctx.env

