After a lot of work, this new version should be stable and more efficient.

• Completly reorganised data collection and storage, making the plugin using less resources (CPU & memory).
• Added a mechanism to not send BungeeCord messages to servers which cannot receive them because they don't have any online player. This prevents the accumulation on the BungeeCord proxy server of messages that couldn't be delivered and are kept in cache to be sent when the servers get an online player. (thanks to @ItzFlip and @TheFancyGamer for reporting the issue).
• Added communication of player messages between servers in a BungeeCord network in order to have the full history of messages (in all servers) when reporting a player (thanks to SiriHackYT for the suggestion).
  (NB: Because of BungeeCord limitations, that messages can only be exchanged if the sending and receiving servers have at least one online player, therefore the full history of messages of 2 players cannot be collected with the current system if the 2 players are connected on 2 different servers).
• Fixed several lines display in report alerts (thanks to @Bermiin for reporting the issue).
• Added an automatic way of updating SQLite database keeping previous data when updating the plugin (it is still advised to make a backup before using that auto update mechanism).
• Improved BungeeCord messages management.
• Attempt to fix the error "Database file is locked" when using the SQLite database.(thanks to ilfarpro for reporting the issue).
• Wrote a lot of automatic tests in order to detect issues more easily.