Add description to help text

SpritePacker/Resources/HelpText.txt

@@ -1,6 +1,8 @@
 SpritePacker {version}, by Starbeamrainbowlabs
 Built at {build-date}
 
+An advanced sprite packing tool
+
 Usage:
     [mono ]./SpritePacker.exe [flags] /path/to/output/file.png [filenames]
 

SpritePacker/Sprite.cs

@@ -50,6 +50,7 @@ namespace SpritePacker
 		public int Right { get { return area.Right; } }
 
 		public int AreaSize { get { return area.Width * area.Height; } }
+		public int MaxSideLength { get { return Math.Max(area.Width, area.Height); } }
 
 		public Sprite(string inFilename)
 		{