Migration to VS2017

* Remove pause to be automated build friendly
* Use 7-Zip instead of WinRar
* Enable parallel builds
* Build improvements
* Push final installer to AppVeyor
* AppVeyor config

* Set version of binaries based on CS_VERSION environment variable
* Use AppVeyor supplied product version
* Automatically generate ProductCode GUID
* Convert version (CS_VERSION) to number (CS_VERSION_NUM)

Improved readability

Update README.md

CMenuContainer object was not destroyed when Start Menu window was closed.

It was referenced by IFrameworkInputPane::AdviseWithHWND call (to be able
to receive input pane notifications). The problem was that dereferencing
(IFrameworkInputPane::Unadvise) was called from CMenuContainer destructor
that is called only when object's refcount goes to zero.

In previous Windows versions it somehow worked, because for some reason
CMenuContainer object was no longer referenced when its window was
destroyed.

Apparently there was some change in IFrameworkInputPane handling in recent
Windows builds (starting with 17692).

To fix the issue we have to call IFrameworkInputPane::Unadvise() when
CMenuContainer's window is about to be destroyed.

Fixed issue related to the cleanup of the accessibility COM objects that
may cause Explorer to crash.

Submitted by Ivo Beltchev.

Essential fixes