bundle2: handle new line in 'outdebug' function Now that we have a prefix, it make sense to assume all output will be on a single line.

bundle2: prefix all bundling debug messages with 'bundle2-ouput:' This makes the origin of the message more explicit.

bundle2: introduce a specific function for bundling debug message The bundling process is very verbose, we would like to be able to hide such output behind a configuration flag and have it more explicitly referencing bundle2. The first step is to gather all these messages in a dedicated function. The same gathering will be later do for debug message issue by unbundling.