cmake and windows builds

[scyptnex]

I noticed there's a cmake branch which is not up-to-date, it seems to work on my version of linux.

Use of (for example) unistd.h mean boxes wont compile in msvcc, but mingw should be fine.

Is the intention to replace the current gnu-make build system?

And if so, with a new CMake system, it would be good to integrate the current testing framework with CTest

[tsjensen]

Yea, I started that branch because I am thinking about switching to a cmake build. This would better integrate with my CLion IDE. Also, in order to solve #1, we need to depend on some external libraries, which would be much easier if we had some more powerful build system. A potential problem is that boxes runs on a large number of platforms, which we want to continue to support (20+).
As for MinGW, that has actually always been our choice for Windows.

[tsjensen]

Thanks for your work on the appveyor support and cmake build system.
It appears to have stalled, but I archived the current state (as far as it was known to me, mostly from PR #35) on a new branch 'scyptnex-cmake', just in case we come back to it.

[scyptnex]

Thanks, unfortunately my real job is more demanding right now. The appveyor standalone support is a bit tricky because the current behaviour uses a mingw/cygwin shell, which is a little tricky to do with appveyor. If we can fix a clear idea on what the cmake behaviour should be then we might be able to phase in support later

[tsjensen]

We are currently fine with the simple build system. While having a cmake based build system would still be great, it's not something I would pursue at the moment.

If you (or anyone else) want to take it up again, that would still be appreciated though!