Support Auto Hide Task Bars on Windows

This is for: https://github.com/adobe/brackets/issues/7555

* Testing recommendations:

Place the task bar on:

1.  Left
1.  Top
1.  Bottom
1.  Right

Test with both auto hide and always visible.

This should be checked on Multiple Monitors as a fair amount of work went in to finding the right solution for multiple monitors.

* Make sure the Maximized size on a monitor without a task bar is the whole monitor
* Make sure the Maximized size on a monitor with a task bar that is not auto-hide works (top/left/bottom/right)
* Make sure that the Maximized size on both monitors is respected if the task bar is shown on all monitors (left/top/bottom/right)
* Make sure that the window adjusts itself when the app bar position or auto-hide flag changes while the app is running.
* Make sure that the size placement accommodates for a hidden Windows task bar if its state was *not* hidden when brackets saved the window placement data and is restarted with a hidden windows taskbar

You will notice a 1px area between the app and the taskbar. This is the taskbar and typical of all apps to give the taskbar an edge to grab.  It *IS* more apparent with a dark border which gives the 1px line a little more contrast and makes it more visible.
krud. I thought I removed this. this was being used to scope the `cef_buffered_dc` object and do some later drawing but that didn't work. I just need to clean this up.