Cannot build since CMake modernization 5e9cb01

[Samonitari]

Hi @slurps-mad-rips !

I like the way you modernized the CMake, even though I am not an expert in build systems, to express it lightly.
However, yaml-cpp cannot be build with the nem CMake version.

Genarator expression is wrong. I had replaced it with if else endif combination...
PROJECT_LABEL "yaml-cpp $<IF:${build-shared},shared,static>"
just won't work as it results in
Could not write lines to file "yaml-cpp.dir\Debug\yaml-cpp.4B5A77C1.tlog\yaml-cpp $<IF: $<BOOL:ON>,shared,static>.lastbuildstate". Illegal characters in path. [T:\m_sw_3rdparty\10.0.17763.0\14.16.27023\yaml-cpp\0.6.3.1\yaml-cpp-build\yaml-cpp.vcxproj]

I'm on CMake 3.13.4

[bruxisma]

Ahh damn. That might have sneaked in from a rebase/squash I did. I had replaced it at some point because 3.4 doesn't support the $<IF:...> generator expression construct. I'll get a better PR in so that #776 doesn't have to comment out the label. Apologies. 😓

[bruxisma]

(Sorry for the delay. I've been swamped with life lately. I'll have a fix up in the next few days)

[jbeder]

I just merged #782, but feel free to do a different/better fix!