Magick.NET 7.0.7.0

Related changes in ImageMagick since the last release of Magick.NET:

• Fixed numerous memory leaks (reference https://github.com/ImageMagick/ImageMagick/issues).
• Fixed issue in the JP2 decoder (http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=32606)