Upgrade to VS 2017

[martingbrown]

I've created a new pull request for this as #700 doesn't seem to be getting anywhere.

I have:

• updated all the projects in all the solutions to Visual Studio 2017.
• updated the projects in the BlogRunner.sln to point to the correct location for their dependencies and made it prefer 32 bit[1].
• written a build.ps1 file for the build as the old build.cmd was having trouble finding MSBuild where VS 2017 installs it. The way MS recommend to find it is with a powershell module.
• changed the old build.cmd to simply call the new build.ps1 script.
• updated the appveyor config to use the Visual Studio 2017 image.
• updated the version number by one minor point. This stops Squirrel from erroring during the build.
• re-targeted the Ribbon project.
• changed some of the projects that were compiling against .Net Framework 2 to compile against .Net Framework 4.6.1

Some things I haven't done:

• I have not fixed the Tistory crash that occurs during the start-up wizard which is fixed by Fix crash caused by addition of Tistory support #721
• I have not fixed the file mapping crash that also occurs during start-up wizard. I assume this is fixed by [WIP] Associate .wpost files with OLW #592

Both these issues are already in the master branch and felt like they were outside the scope of this change.

[1] The projects in the BlogRunner.sln appear to be duplicated in both $/Utilities/BlogRunner/ and $/src/Managed/ I only modified the one in the utilities directory as the other seemed to be set up ok. I made it prefer 32 bit as the output of the write.sln projects are mostly x86 even though the build is set for Any CPU.

[dariuszparys]

@jongalloway PR works on my machine

[jongalloway]

Works for me. Thanks so much for a great pull request and thorough description.