Use SharpGenTools.Sdk for Codegen (#988)

* Preliminary updates to use SharpGenTools.Sdk instead of built-in SharpGen.

* Clean up now unneeded files.

* Update to newest SharpGenTools.Sdk.

* Use SharpGen.Sdk 1.0.0-rc1.

* Update to new ci build of SharpGenTools.

* Remove unneeded external files and leftover files from SharpGen/SharpCli

* Make all mapping files in use be SharpGenMapping MSBuild items. Integrate external doc comments via MSBuild items. Refactor global rules to ensure specific projects can correctly override them.

* Update to new documentation system.

* Updated to SharpGenTools 1.0.0-ci222.

* Stop tool projects from picking up the production project settings.

* Generate code in a non-parallel build so we completely avoid locking issues with multiple builds sharing SharpGen  files (which is an issue here because of the heavy customization).

* Add Dummy pack target for tools packages.

* Upgrade to SharpGenTools.Sdk 1.0.0-ci237 make code changes as needed.

* Upgrade SharpGenTools.Sdk and add global namespace overrides.

* Upgrade to SharpGenTools 1.0.0-ci244 to use builtin callback marshalling

* Upgrade to SharpGenTools.Sdk 1.0.0

Author: jkoritzinsky

Build/SharpDX.props

@@ -74,6 +74,7 @@
   <PropertyGroup>
     <PreBuildEvent>REM $(SolutionDir)Source\Tools\SharpDoc\Bin\$(ConfigurationName)\SharpDoc.exe --config config.xml</PreBuildEvent>
   </PropertyGroup>
+  <Target Name="Pack" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">