shifted the form around to make sure we get the boxes clicked as expected
simplifying how the start/end dates are updated

we’re setting them at the same time now to make sure we don’t get “end
before beginning” sort of errors;
resolves http://bugs.web2project.net/view.php?id=1469
updated the date handling to never change the end time, only the date on a task log update

Resolves http://bugs.web2project.net/view.php?id=1396
fixes for phpdoc