Add UNIX man pages

[anatol]

I found this tool works great on my Linux Arch box. Thanks a lot for it!

One thing that worth improving is to add a UNIX man page. There is already tutorial so having the same information in man file would be very useful.

Thanks.

[xor-gate]

This should be in the same category when commandline argument parsing is refactored for milestone 2.0.0. Then we can generate man pages.

[xor-gate]

@alx741 I have refactored some CMake files and add pandoc generation in debug builds. For release builds it is skipped.

See 1ade678

[xor-gate]

It seems I have broken the build on cmake 2.8. I'm currently using cmake 3.5 so I need to find out on another machine with cmake 2.8. Will fix ASAP on another machine.

[xor-gate]

Unix man-pages are merged into master.