Add module providing logging features

[ecourtois]

A log module is required to properly handle:

• debug messages, that can be disabled at compile time,
• warning/error messages,
• log messages, that could also be sent to the Copilot.

This will also replace COGIP_DEBUG_COUT macro.

[gdoffe]

This issued has been partially adressed, through #200 .

Only finding a way to send log or maybe more error codes to copilot is still needed.