fix saved search grouping not being applied correctly (fixes issue #1969)

Conflicts:

	core/classes/B2DB/TBGIssuesTable.class.php
fix milestone todo list not being applied properly on page 1
change quicksearch order so that quicksearch shows newest first

Conflicts:

	core/classes/B2DB/TBGIssuesTable.class.php
improve column name and alias caching
change time offset implementation from fixed hours to DateTimeZone based offsets to include all possible offsets and use correct DST
add missing functions