More work on the upgrade path to be sure all the necessary modules get enabled and that date_popup formats get adjusted to formats that work with that module.

Make sure new required modules get enabled during the update, should have made the module list an array.

Remove database timezone handling by rolling back to previous version that used offsets instead. Based on problems noted in #218479 and #220663, we cannot count on database timezone handling to be available in MYSQL or work consistently with the timezone names that PHP uses in POSTGRES, so trying to do timezone conversions in the database is not going to work.

Synch with D5.2 version.

#218479 Add more information about db timezone support to the INSTALL.txt file and move the requirements test to the Date Timezone module.

Rework the logic for handling the date timezone and converting from and to the db storage timezone. Finally realized the widget cannot do the timezone transformation, the widget must always be handling a date in the same timezone so validation and other processes can work correctly no matter what route the form takes. It will be up to the field, not the element, to transform the date from gmt to the local timezone when the date is retrieved from storage and back again before saving it.

This is the first of a series of updates to get this change implemented. Things are likely to be buggy untill all these changes are reworked and committed.

#178408 make sure $ret uses update_sql, patch by moofie, also cache date_views array so we don't have to re-create it on every page.

Move override of site and user timezone setting into its own module so it can be turned on or off and removed once this is done by core. Also make PHP4 handling into a module instead of an include file so it can be turned on or off and removed once core no longer supports PHP4.

Very preliminary rewrite of Date API to become version 5.2. Not ready to be used yet! Still coming is rewrite of date and calendar module to use new API.