Make `input_formats` and `format` work consistently across `date`, `datetime`, and `time` fields and widgets.

[Tai Lee]

Currently, there are some inconsistencies in what form fields and widgets we have available for date, datetime, and time data. There are also inconsistencies in how the format argument applies to the widgets, and the input_formats applies to the fields.

1. DateTimeInput and TimeInput exist, DateInput doesn't.
2. DateTimeInput accepts format, but TimeInput doesn't.
3. SplitDateTimeField doesn't use SplitDateTimeWidget by default.
4. SplitDateTimeField doesn't allow the user to specify input_formats.
5. SplitDateTimeWidget uses two TextInput widgets, instead of TimeInput and the missing DateInput (and thus doesn't allow the user to specify formats).
6. django.contrib.localflavor.generic.forms is missing SplitDateTimeField.
7. The documentation is sparse on detail for SplitDateTimeField, DateTimeInput and TimeInput.

This patch:

1. Adds DateInput, which accepts format, and is used for DateField by default.
2. Adds format as an argument to TimeInput.
3. Uses SplitDateTimeWidget for SplitDateTimeField by default.
4. Adds input_date_formats and input_time_formats as arguments to SplitDateTimeField.
5. Uses DateInput and TimeInput for SplitDateTimeWidget, and passes through date_format and time_format through to DateInput and TimeInput as format, respectively.
6. Adds SplitDateTimeField to django.contrib.localflavor.generic.forms.
7. Adds documentation for all of these changes.
8. Adds tests for all of these changes.

[Tai Lee]

Another option would be to use settings.*_FORMAT as the default if no format is provided. This would make it easy to configure a consistent date format across a whole site, including forms.

[Tai Lee]

On second thoughts, it looks like settings.*_FORMAT uses a slightly different format and supports some options not compatible with strftime, etc.

[Tai Lee]

Removed redundant line from generic SplitDateTimeField and improved documentation.

[Tai Lee]

Set default date/time format for SplitDateTimeWidget as class attribute, so it can be overridden in a subclass.

[Tai Lee]

Updated to r9843.

[Tai Lee]

Looks like SplitDateTimeField does use SplitDateTimeWidget by default in r9843, so I've updated the patch to work on trunk again.

[Claude Paroz]

+1 for this patch. Was bitten today with the missing format of the TimeInput widget...

[(none)]

Milestone post-1.0 deleted

[Karen Tracey]

(In [10115]) Fixed #8962 -- Consistently support format and input_format in the various (individual, combined, split) date and time form fields and widgets.

Many thanks to Tai Lee for doing all the work here.

[Jacob]

Milestone 1.1 beta deleted