Add CLI features to manage virtual screens

[waydabber]

Make existing CLI features address virtual screens + add new features specifically to manage virtual screens.

[waydabber]

Added two commands to create and discard a device (virtual screen):

• create - Create a device. You need to specify deviceType=VirtualScreen. You can add other set operation parameters to configure the virtual screen or alter its identifiers from default. If an identifier is not provided, the app will provide a default or (if it makes sense) random value.
• discard - Discard a device. You need to specify deviceType=VirtualScreen and the additional device identifiers using identification parameters to narrow the devices you want to discard. Warning: without identifiers, the app will discard all matching device types without question and ability to undo - be careful with this!

There are various options that work with create, set and get to define and manage a virtual screen:

• virtualScreenName - Defines the name of the virtual screen Virtual screen management feature.
• virtualScreenSerial - Defines the serial number of the virtual screen Virtual screen management feature.
• virtualScreenVendorNumber - Defines the vendor number of the virtual screen Virtual screen management feature.
• virtualScreenModelNumber - Defines the model number of the virtual screen Virtual screen management feature.
• aspectWidth - Aspect width of the virtual screen. Virtual screen management feature. A contiguous range of values are accepted.
• aspectHeight - Aspect height of the virtual screen. Virtual screen management feature. A contiguous range of values are accepted.
• sizeInch - Diameter of the virtual screen in inch. Virtual screen management feature. A contiguous range of values are accepted.
• multiplierStep - Multiplier step of the generated resolutions (multiples of aspect width and height). Virtual screen management feature. A contiguous range of values are accepted.
• limitMultiplierSize - Enable/disable multiplier limits. Virtual screen management feature. A contiguous range of values are accepted.
• multiplierMinWidth - Multiplier limit - height width. Virtual screen management feature. A contiguous range of values are accepted.
• multiplierMinHeight - Multiplier limit - height minimum. Virtual screen management feature. A contiguous range of values are accepted.
• multiplierMaxWidth - Multiplier limit - width maximum. Virtual screen management feature. A contiguous range of values are accepted.
• multiplierMaxHeight - Multiplier limit - height maximum. Virtual screen management feature. A contiguous range of values are accepted.
• flipped - Virtual screen flipping. Virtual screen management feature. Bool value (on or off) must be specified.
• virtualScreenHiDPI - Enable HiDPI resolutions in the resolution list of a virtual screen. Virtual screen management feature. Bool value (on or off) must be specified.
• useResolutionList - Use custom resolution list instead of generated resolutions based on the aspect ratio and multiplier. Virtual screen management feature. Bool value (on or off) must be specified.
• resolutionList - Resolution list in WIDTHxHEIGHT,[WIDTHxHEIGHT[,...]] format. Virtual screen management feature.

[waydabber]

Some examples.

Creating a virtual screen (with an aspect ratio of 12:10):

betterdisplaycli create -devicetype=virtualscreen -virtualscreenname=MyVirtual -aspectWidth=12 -aspectHeight=10

Connecting a created virtual screen:

betterdisplaycli set -namelike=virtual -connected=on

Discard a virtual screen (use any identifier parameters to narrow the virtual screens to be discarded):

betterdisplaycli discard -namelike=virtual

Discard all virtual screens (rather dangerous, will happen with no comment):

betterdisplaycli discard

Rename a virtual screen from MyVirtual to TestVirtual:

betterdisplaycli set -name=MyVirtual -virtualscreenname=TestVirtual

Please note that while name is an identifier parameter to specify the device(s) you work on, virtualScreenName is a create/set/get parameter to modify the name of the virtual screen. The same with serial, modelNumber, vendorNumber.