keyword documentation is inconsistent

[opalmer]

The keyword documentation is inconsistent in a few places. For a function such as:

def foobar(a, b=None):
    pass

It should be expected to be documented like this:

def foobar(a, b=None):
    """
    Something about this function

    :param type a:
        About parameter a.

    :keyword type b:
        About keyword b
    """

Currently however there's a function functions which don't use the keyword directive.