Misc doc cleanups.

:attr:`~django.forms.extras.widgets.SelectDateWidget.years` attribute is set

for a :class:`~django.forms.extras.widgets.SelectDateWidget`::

    from django.forms.fields import DateField, ChoiceField, MultipleChoiceField

    from django.forms.widgets import RadioSelect, CheckboxSelectMultiple

    from django import forms

    from django.forms.extras.widgets import SelectDateWidget

    BIRTH_YEAR_CHOICES = ('1980', '1981', '1982')

                                ('black', 'Black'))

    class SimpleForm(forms.Form):

        birth_year = DateField(widget=SelectDateWidget(years=BIRTH_YEAR_CHOICES))

        birth_year = forms.DateField(widget=SelectDateWidget(years=BIRTH_YEAR_CHOICES))

        favorite_colors = forms.MultipleChoiceField(required=False,

            widget=CheckboxSelectMultiple, choices=FAVORITE_COLORS_CHOICES)

            widget=forms.CheckboxSelectMultiple, choices=FAVORITE_COLORS_CHOICES)

See the :ref:`built-in widgets` for more information about which widgets

are available and which arguments they accept.

template is evaluated, and **tags**, which control the logic of the template.

Below is a minimal template that illustrates a few basics. Each element will be

explained later in this document.::

explained later in this document.

.. code-block:: html+django

    {% extends "base_generic.html" %}