Deleting the log_messages

[angoca]

Deleting the log_messages (either for a particular logger or the whole table)

Reported by Edward Slattery

[angoca]

Messages in LOGS table are considered post-mortem. For this reason, dealing with these rows is outside the scope of this project, and this kind of deletion on a particular column o part of a column implies custom design which is not the aim of this project.