Refactor CMake files

[jgvictores]

A great number of new CMake features would make our CMake files cleaner and better.

[jgvictores]

As commented with @PeterBowman this issue is mainly related with all the exporting dependencies for (...) quite manually for now... comments.

[PeterBowman]

I'm afraid we are somehow constrained by having to deal with Debian's outdated (6.0) SO. Of course, these lines could be improved a bit anyway, in that respect I found YARP's use of CMake a valuable source for discovering features and good (I hope so) practices in dealing with project configuration. I noticed yesterday some ongoing work targeted towards next YARP releases to support CMake 3.0, let me link it here just for interest's sake: robotology/yarp@215c823. Keep in mind that teo-body is stuck at 2.8.9 which, incidentally, is guaranteed to be supported in current YARP distributions, thus many ideas could be borrowed from them for use in this repo.

[PeterBowman]

Most of the constraints mentioned in my earlier comment could be collaterally solved with #118.

[PeterBowman]

Example: roboticslab-uc3m/kinematics-dynamics#14.

[PeterBowman]

WIP at the fix-26-cmake branch. I wonder if using YCM to fetch ColorDebug was a good choice... I'm unable to configure it on my PC with CMake v2.8.9 (same as Debian 6.0) because of a Unknown CMake command "write_basic_package_version_file" error at CMakeLists.txt#L102. What happened: YCM tries to download CMakePackageConfigHelpers.cmake from CMake's GitHub repo at rev. 3.1.3, but for some reason it gets an empty file (!) as a result, which then shadows the local version shipped with CMake itself.

I need to test it on Debian 6.0, but from what I recall, YCM didn't work with this same CMake version on Ubuntu Precise.

[PeterBowman]

I managed to solve that by digging in our own installation guides: install-cmake.md#openssl-support. Funnily enough, I run into this same issue a few months ago, identified the cause and added that section in install-cmake.md. Now I need to find out whether CMake packages are compiled with OpenSSL support, otherwise tell users to compile it according to the installation guide.

Let me express my relief with a bunch of fine sarcasm.

[PeterBowman]

Now I need to find out whether CMake packages are compiled with OpenSSL support

Confirmed, Debian 6.0 backports support SSL.

[PeterBowman]

Done at 891df8f.