Boost in LyX

[Yuriy Skalko]

> It compiles flawlessly with MSVC 2019 (16.7.1):
> 
> C:\Program Files (x86)\Microsoft Visual Studio\2019\Community>cl /v
>> Microsoft (R) C/C++ Optimizing Compiler Version 19.27.29111 for x64
>> Copyright (C) Microsoft Corporation.  All rights reserved.
>>
> 
> However, it fails when linking (but I'm not sure it's related, it's been at
> least ten commits since my last build), with things related to
> lyx::support::checksum

Yes, I've had similar link errors. The Cmake should be reconfigured, so 
it can see new source file checksum.cpp.

Yuriy