Fix the capture of the errors from the methods for display.
Fixes the setting of the tasks' end data and completion percentage on task
log deletion. The best method would be to implement a stack but it would
require locking code to avoid corruption due to multi-user simultaneous
manipulation and in case of corruption the fix would be cumbersome.
This method is not very smart but can recover automatically from corruption
just by editing the most recent task log.

THIS FIX REQUIRES A DB UPGRADE.
Fix to show problem task logs with the proper background; requires
additional parameters to the createCell method of HTMLHelper (the defaults
keep the usual behaviour).
Fix to add the time from the original end date to the task log's end date.
The task's end date, after inserting a task log, always had a 00:00 time.
Two in one fixes:

- Hide the billing field if there are no values to choose from;
- Align the calendar icons vertically.
Fix of a fix; now the task validation code (dependencies tests) should
work properly. It also uses a simpler and more reliable test for getting
the most up to date dependencies for the task.
Uniformized the handling of the minimal view of tasks in relation to
the selection checkboxes, that were being shown in 'View project', where
it was not possible to do anything with them.
The 'Print to PDF' button now prints the same date range as is visible
on page.
Several fixes related to PDF Gantt charts and the 'My Tasks To Do' page:

- The user selection in 'My Tasks To Do', with an 'admin' user, is now
  remembered across 'Redraw' presses.
- When charts are printed from 'My Tasks To Do' the task filtering by user
  now works.
- The splitting of tasks across PDF pages should now work properly, when
  used from 'My Tasks'.
Another fix for the calendar views, concerning task and event filtering.
Undoes a fix that was applied on the getTaskLinks function that made it
incorrectly apply a fixed exclusive filter.
The task links shown on 'Day View' ('Tasks assigned to others') are from
projects of which the current user is the owner. Previously all projects
were listed.
Fix to differentiate between tasks assigned to me and assigned to others
(but from projects owned by me) in the calendar views.
CSS additions to style the 'others' tasks in the calendar views.
Fix for a crash in Gratt chart generation from the button on the 'Tasks'
page.