Rewrite event module to use datetime sql format

Here is a list of functions that need looking at:

event.module:

event_link event_page (lots of changes...) event_type event_term event_feed event_ical event_calendar_month event_calendar_week event_calendar_day event_calendar_table event_calendar_list event_calendar_rss event_calendar_ical event_get_calendar (lots of changes) event_calendar_data _event_date _event_day_of_week _event_day_of_week _event_mktime _event_user_time _event_user_date event_form_date event_validate_form_date _event_nav event_block event_block_upcoming event_form_alter event_nodeapi event_set_range event_dst Many of these functions aren't actually affected by the database change but by the values being read from it and passed on.

event_timezones.inc: Change event_is_dst for new format.

event.theme: Change following functions for new format: theme_event_calendar_date_box theme_event_empty_day

ical.inc: ical_export ical_import _ical_calcTime _ical_calcOffset

event.install: Alter schema Add upgrade path

The rewrite is nicely progressing, however a lot of bugs, especially in calendar rendering still remain. Testing is of course welcome. There is an upgrade path provided which worked for me if done on the same machine.

Don't use on production servers.

This has progressed to a point where I dare to mark it fixed. There are probably still some bugs lurking, but the conversion as such is now complete.