Fix migration script

I *think* SQL requires single quotes here instead of double quotes.

At the very least, Postgres was erroring with this message:

SQLSTATE[42703]: Undefined column: 7 ERROR:  column "imp.%" does not
exist
Fix quoting.
Remove useless check.
Horde_Core is not required
Fix form variable names
Bug #12130: Need to also check if HTML is part ID 1, not just a child of part ID 1
Fix undefined variable.
[jan] Only send update notifications for local calendars.
[jan] Don't send notifications for all recurrence exceptions when deleting events.
More fixes upstream (tweaks to patches previously applied here)
Better sanity checking for broken CSS
Inform the user if broken CSS data exists in the message
Convert non-period decimal points to periods
The phpdoc states this method can take IMP_Maillog:: constants. Make it so.
Merge branch 'master' into imp_6_1

Conflicts:
	imp/lib/Mime/Viewer/Html.php
	imp/migration/3_imp_maillog_update.php