Support Display Toggle

## Prerequisites
- [x] I have searched open and closed issues for duplicates.

## Feature
**Is your feature request related to a problem? Please describe.**

Currently the tablet area is mapped to all the available screen area. This is problematic when you have multiple monitors, because that means you can only use half the tablet when drawing in an application on one monitor.

**Describe the solution you'd like**

I understand that Wacom on Windows has a Display Toggle function, which enables you to quickly switch between working on all of your monitors and working on individual monitors. I assume people usually map one of the tablet buttons to this action. More info:
http://101.wacom.com/UserHelp/en/DisplayToggle_Opaque.htm

**Existing work**

See above

**Describe alternatives you've considered**

One alternative solution would be to have settings to change how the tablet is mapped to the screen area:
http://101.wacom.com/UserHelp/en/Mapping.htm
But, that seems like quite a hassle if you frequently want to change this and not the easiest kind of settings to design and implement.

**Additional context**

The issue names no files, tests, or entry points. Start by locating the repository code responsible for tablet-to-display mapping and reviewing how monitor selection is currently handled; done means a user can switch between all monitors and an individual monitor as requested.

Written by the indexing model from the issue text.