Support cmake 3.8 and higher only

[ilya-lavrenov]

• Removed legacy cmake files, because they don't even work
• Actualized minimum cmake version for root CMakeLists.txt file and now it becomes 3.8
  • Most recent user feature is target_compile_features with cxx_std_17 or cxx_std_11 arguments
  • PCH files (requiring cmake 3.16) are optional already and it's not a mandatory to build the product.
• Minor improvements to cmake files
• Tested with cmake 3.8, 3.14 and 3.25.2

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[ilya-lavrenov]

Hi @dbaileychess,
Could you please have a look at the PR? The change is quite simple

[dbaileychess]

@ilya-lavrenov I left 2 comments the other day that haven't been resolved yet.

[ilya-lavrenov]

@ilya-lavrenov I left 2 comments the other day that haven't been resolved yet.

hm, I don't see any comments in the PR..

[dbaileychess]

oh, that's a stupid change by github. My comments show up in my view but have a new pending chirp that seems new to me.

[ilya-lavrenov]

@dbaileychess please, have a look.

Now, cmake files look generic enough to support cmake version 3.8 and higher, which allowed to remove legacy non-working cmake script. I've explicitly mentioned places why we need at least 3.8.

[dbaileychess]

Thanks, this is a better approach than fixing the legacy. Just a few comments.

[dbaileychess]

Thanks, I appreciate the fast turn around!