CMake: Various fixes in libspawner project.

[cher-nov]

• Add lost buffer.h to the list of headers.
• Fix usage of LIBUNIX variables instead of LIBPOSIX, so IDE projects were generated incorrectly.
• Reorder headers and sources by alphabet for convenience.

[klenin]

@ViktorPegy, please review. My suggestion would be to remove sorting to avoid conflicts and merge the rest.

[cher-nov]

@klenin, @ViktorPegy: attached a merged version of CMakeLists.txt from this PR and this one. Line endings are LF.

Attach: CMakeLists.txt

If this PR will be merged, @ViktorPegy could perform "fetch & rebase" from and onto upstream, replace conflicted CMakeLists with this one and finish rebasing.

This is just a suggestion. If you decide to remove sorting, I will do this.

[dsbogdan]

Hi cmake file(GLOB ...) feature may help to eliminate manual roll out of all project filenames (a patch is rather simple).

just my 2c.

[klenin]

@dsbogdan: not so simple, see 9ceddd432a2355809596b199ca977926aaeca98e Maybe @rotanov will comment

[rotanov]

I tried to bring GLOBs back now and succeeded, so GLOBs are the way, sure. I have only slightest idea now of why I removed GLOBs. Here are some pros and cons of using GLOB:

pros:

• you won't forget to add new file to CMakeLists.txt since it's done automatically
• you are forced to keep your directories clean of "trash" files

cons:

• if you have several intersecting sets of files for each project then you are forced to put their intersection into one common folder and what's left from each set to each own project folder. This is artificial structure enforced to you by using GLOB
• you can't see listing of files in explicit form in-place, instead you have to generate project or do the GLOB thing in your brain

I think the first point of cons was the deal breaker for me. And I'm basically always prefer explicit to implicit. e.g. implicit cast

[klenin]

@cher-nov: So please resubmit useful parts separately. Generally, please do not mix small fixes with large breakage within a single PR.