Restore "warn_suppress" variables and mark them as YARP_UNUSED

This should suppress all relative -Wunused and -Wunused-result warnings
with all the different compilers
Cleanup
[YARP_OS/Log] Check arguments of the c-style debug functions

This ensures that the arguments supplied have types appropriate to the
format string specified, and that the conversions specified in the
format string make sense. On gcc the warning is enabled by -Wformat.
[YARP_OS/Log] Improve reading of debug environment variables

Trace is now disabled when debug is disabled
[YARP_OS/Log] Simplify print_callback and forward_callback implementations

Hopefully it will not impact performances
[YARP_OS/Log] Use the full name for colored_output variable in color macros
[YARP_OS/Log] Remove extra space in final forwarded output line
[YARP_OS/Log] Use ACE_OS::snprintf instead of sprintf
[YARP_OS/Log] Fix -Wformat-security warnings
[YARP_OS/Log] Remove no longer used variables
[yarplogger] Make trace light grey instead of purple
[yarplogger] Initialize QApplication after ResourceFinder

On linux, QApplication "eats" the --name argument
[yarplogger] Use ResourceFinder singleton instead of passing one around
[YARP_OS/Log] Refactor logging functions and add non forwarding macros
[YARP_OS/Log] Print thread id when verbose output is enabled
[YARP_OS/Log] Add "Component" logging macros
[YARP_logger] Parse component tag
[yarplogger] Show component in a separate column
[YARP_OS/Log] Add YARP_IS_YARPRUN environment variable and extra tags

If this variable is enabled, log forwarding is disabled and the output
is formatted as the forwarded one.

Also add extra tags to the pristine output:
 * filename
 * line
 * function
 * thread_id
[YARP_logger] Read the new tags from log