Import format_size and format_size_number from old launcher, improved Task progress reporting, use aggressively cached file verification for Task unless we're running a repair (speed up updating)

lib/common.rb

@@ -6,4 +6,21 @@ module W3DHubLauncher
       "/etc/ssl/ca-bundle.pem"              # Some other distros
     ].find { |path| File.exist?(path) }
   end
+
+  def self.format_size(bytes)
+    case bytes
+    when 0..1023 # Bytes
+      "#{bytes} B"
+    when 1024..1_048_575 # KiloBytes
+      "#{format_size_number(bytes / 1024.0)} KB"
+    when 1_048_576..1_073_741_999 # MegaBytes
+      "#{format_size_number(bytes / 1_048_576.0)} MB"
+    else # GigaBytes
+      "#{format_size_number(bytes / 1_073_742_000.0)} GB"
+    end
+  end
+
+  def self.format_size_number(i)
+    format("%0.2f", i)
+  end
 end