Formerge

Marco,

Thanks for your tips.

I've created a new branch in my repo so that I can work on other features without them being automatically added to the pull request before they are ready.  

I have cancelled the previous pull request and am creating this new one with all the work I have done so far.

To recap, three main changes are:

- Ability to show/hide non-working hours in a day column
- More intelligent snap for start/end of tasks when moving or resizing them
- Ability to set an allowable time window for tasks, which displays when the task is hovered over or is being moved.  The style of the time window can be controlled in the css file.  The time window is not strictly enforced (ie the user can move the task outside the window), but if the task is outside the time window it goes red.