Logger: new Log writer API

the Logger is a new API component that aims to provide communication channels
for all worker threads available, so they can write their own log messages. To
accomplish this from the stack point of view, a new worker thread monitor the
events on Kernel pipes and flush the logs every 3 seconds to disk.

The pending part at this point is to let the API use the LogDir configuration
directive to store the log messages.

Signed-off-by: Eduardo Silva <edsiper@gmail.com>
Logger: use LogDir directive and headers cleanup

Signed-off-by: Eduardo Silva <edsiper@gmail.com>
Logger: add date and time to log entry

Signed-off-by: Eduardo Silva <edsiper@gmail.com>
SSLS and Websocket packages adjustments

Signed-off-by: Eduardo Silva <edsiper@gmail.com>
Core: re-define duda_request_t typedef

Signed-off-by: Eduardo Silva <edsiper@gmail.com>
MariaDB: add result fields to on_result callback

Signed-off-by: swpd <swpdtz@gmail.com>
Merge commit '0a787af0c57b9acc08e6594d590d2358fbf5db89' into mariadb
MariaDB: add field number to on_result callback

Signed-off-by: swpd <swpdtz@gmail.com>
Merge commit '1e993fc79f58afc37b67a67b6a32ea8baf420324' into mariadb
Update README.md
MariaDB: let user free private data of on_row callback

Signed-off-by: swpd <swpdtz@gmail.com>
Merge commit '252d6bbb222df18b2a90ec87470e9a59e0836f5e' into mariadb
MariaDB: add FAQ

Signed-off-by: swpd <swpdtz@gmail.com>
Add services subdirectory

Signed-off-by: swpd <swpdtz@gmail.com>
MariaDB: make private data accessible through the life cycle of a query

Signed-off-by: swpd <swpdtz@gmail.com>
Merge commit 'e6ac42b253134d5dce4035ff3d4d2f51b6ecde43' into mariadb
MariaDB: fix parameter order

Signed-off-by: swpd <swpdtz@gmail.com>
Merge commit 'f47c268c801b4b5751a36bc49c9145b4b6c7f564' into mariadb
Merge commit '46ef59a839c9f8449740521d3913c910207e4049' into mariadb