New header extension in color-debug, now as a hard dependency

[PeterBowman]

The color-debug project has been long-since used as a set of convenience macros for achieving colored printf calls in C/C++ code. In spite of being a C-only set of preprocessor definitions, its main (and only) header retained a .hpp extension which did not reflect the original intention of supporting C-language code consumers, too. We have decided to finally take the step and rename that header: from ColorDebug.hpp to ColorDebug.h. Additionally, we are now taking advantage of CMake targets, and the usual COLOR_DEBUG_INCLUDE_DIRS variable is no longer set. References:

• Use CMake targets color-debug#11
• Change extension of header file color-debug#12
• project's README.md

Backwards compatibility with older code has been preserved (by means of a convenient symlink), as long as modern color-debug is consumed as a system-installed project (that is, don't forget to make install even if CMake founds a local build/ instance somewhere in your local directories). This change is being applied to all affected repos across the roboticslab-uc3m GitHub organization, thus we advise you to download and install the latest color-debug from the web. Also, this project is no longer suitable for orchestration and management via YCM, which means that now it's being treated as a hard dependency (as well as YCM itself, see #66).

cc @roboticslab-uc3m/roboticslab.