PSThar - Get-TileProperties

My goal with the predefined PSThar cmdlets is to provide easier access to the project than is afforded by the normal API. Mostly, that means handling the boring bookkeeping for the user. I already made a getter and setter for level tiles; today I started the pair for tile properties.

So as to not force extensions to take a dependency on FleexCore 2 (FMod), Abiathar translates tileinfo entries to ULongs and provides some helper methods to reconstitute the meaning from those numbers. Those aren't super easy to work with from script, so I made a class with a bunch of read-only properties to represent the tileinfo for a single tile. Get-TileProperties takes a -Background or -Foreground switch, plus a tile ID, and returns one of those objects. My plan for the setter is to give it a bunch of optional switches to alter one or more parts of a tile's tileinfo.

I also noticed that calling $Abiathar.ViewState.RerenderSelTiles() does nothing from script because the pipeline is run on a different thread than the main form's UI. To fix that, I added the call to the method on the PSThar form that cleans up after script completion.