Logging: Add log levels to output

This commit adds log levels to the output. In systemd, it makes colored
lines, otherwise it's probably just a number. Bees is very chatty, so
this paves the road for log level filtering.

Signed-off-by: Kai Krakow <kai@kaishome.de>

lib/extentwalker.cc

@@ -6,7 +6,6 @@
 #include "crucible/limits.h"
 #include "crucible/string.h"
 
-
 namespace crucible {
 	using namespace std;