addition of multi-render app support and log output adjustments

[av-romann]

(not sure what's gone wrong with the spacing. I may withdraw and resubmit if it's an issue)

The configuration and rendering has been updated to allow for an arbitrary selection of multiple render tools, with independent render control.
There's some small pre-work done to allow selective triggering of render apps via the console, but that part hasn't been implemented yet.
There are also some console output changes to better distinguish which component is doing the reporting.
This is a breaking change to the config file format, which now looks like this (first version, without rationalisation of properties):

 "Renders": {
    "Global": {
      "EnableRenders": true,
      "RenderAppBinPath": "",
      "RenderAppOutputPath": "",
      "RenderInterval": 240.0,
      "RenderAppGlobalArgs": "",
      "RenderAppTasks": [],
      "LowPriority": false
    },
    "bedrock-viz": {
      "EnableRenders": true,
      "RenderAppBinPath": "C:\\Minecraft\\Tools\\bedrock-viz.1.7\\bedrock-viz.exe",
      "RenderAppOutputPath": "test\\bedrock-viz",
      "RenderInterval": 240.0,
      "RenderAppGlobalArgs": " --shortrun --no-force-geojson --detail --db $WORLD_PATH --outdir $OUTPUT_PATH ",
      "RenderAppTasks": [
        "--html-most --slices --all-image"
      ],
      "LowPriority": false
    },
    "papyruscs": {
      "EnableRenders": true,
      "RenderAppBinPath": "C:\\Minecraft\\Tools\\papyruscs\\PapyrusCs.exe",
      "RenderAppOutputPath": "test\\papyruscs",
      "RenderInterval": 240.0,
      "RenderAppGlobalArgs": "-w $WORLD_PATH -o $OUTPUT_PATH --htmlfile index.html -f webp -q -1 --rendermode Heightmap",
      "RenderAppTasks": [
        "--dim 0",
        "--dim 1",
        "--dim 2",
        "--dim 0 -p underground",
        "--dim 0 -p aquatic"
      ],
      "LowPriority": false
    }