Create a viewer for SWEEP animation files

[mkovacina]

The original SWEEP viewer was written in PowerC, drawing directly to the full-screen in DOS mode.
The original source code is currently unavailable.

A second SWEEP viewer was written in Java around 1999.
This source code can be found here.

Something other than Java is needed for animation viewing.
Eventually something web-based will be desired for viewing, but currently a .NET Core-based WinForms app will suffice.

Features

• read and display a SWEEP animation file
• the ability to pause an animation
• the ability to restart an animation
• a scrubber for navigating through an animation
• arrow keys can advance frame-by-frame when paused
• the frame number should be visible
• the number of agents should be displayed
• there should be a display of the the different support grids
• the current support grid should be selectable
• there should be a multi-grid view to display multiple support grids views simultaneously

[mkovacina]

In the viewerjs subfolder, a basic viewer has been implemented using Javascript and the Canvas element.