Add Doxygen 1.8.18.0 (#761)

* Add Doxygen 1.8.18.0

* Fix file naming

manifests/DimitriVanHeesch/Doxygen/1.8.18.yaml

@@ -0,0 +1,18 @@
+Id: DimitriVanHeesch.Doxygen
+Version: 1.8.18
+Name: Doxygen
+Publisher: Dimitri van Heesch
+License: Copyright © 1997-2018 by Dimitri van Heesch.
+LicenseUrl: http://doxygen.nl/index.html
+AppMoniker: doxygen
+Tags: documentation, generator
+Description: Doxygen is the de facto standard tool for generating documentation from annotated C++ sources, but it also supports other popular programming languages such as C, Objective-C, C#, PHP, Java, Python, IDL (Corba, Microsoft, and UNO/OpenOffice flavors), Fortran, VHDL and to some extent D.
+Homepage: http://www.doxygen.nl/index.html
+InstallerType: exe
+Installers:
+  - Arch: Neutral
+    Url: http://doxygen.nl/files/doxygen-1.8.18-setup.exe
+    Sha256: 0F0C7A4B37E083C67499318D66AB4AA3EDE1B378934E563CF1B1508B3ECDD70B
+    Switches:
+      Silent: /VERYSILENT
+      SilentWithProgress: /VERYSILENT