Adding the GPG extension

Author: DougSalt

extensions/gpg-1.0.0.zip

@@ -362,6 +362,18 @@ This version is for NetLogo 6.1 and above"""
     homepage: "https://github.com/cstaelin/Pathdir-Extension"
     downloadURL: "https://raw.githubusercontent.com/NetLogo/NetLogo-Libraries/6.1/extensions/pathdir-3.1.0.zip"
   }
+  {
+    name: "Gnu Pretty Good Privacy"
+    codeName: "gpg"
+    shortDescription: "Gnu Pretty Good Privacy (GnuPG) Extension"
+    longDescription: """Implements a NetLogo extension that utilises GnuPG privacy suite to decrypt data that is encoded symmetrically or asymmetrically.  This will allow for the secure storing of sensitive data in public repositories as these keys can be tailored to specific individuals or groups of individuals.  Additionally this allows the absolute destruction of publically available data providing the it can be proven that the keys for such data no longer exist.
+
+Note GnuPG must be installed in the command path.
+"""
+    version: "1.0.0"
+    homepage: "https://github.com/DougSalt/gpg.git"
+    downloadURL: "https://raw.githubusercontent.com/NetLogo/NetLogo-Libraries/6.1/extensions/gpg-1.0.0.zip"
+  }
   {
     name: "Physics"
     codeName: "phys"