Custom Date field improvements

Make following changes to civicrm_custom_field table

• add date_format varchar 64
• add time_format int
• drop date_parts

UI changes.
If user selects Custom Field of type Date, instead of existing date parts we should give 2 selects ( date_format and time_format )

So custom field should be rendered based on defined format for date and time.

Make the changes in entire code base to work with new schema changes.

---------Original Post ----------------
http://forum.civicrm.org/?topic=7150 - CiviCRM exposes both PHP- and POSTIX-style date notations in its UI. We should standardise on either.