Added new loggers and improved labels in Admin UI

Change details
- Added three new Loggers, with their configuration:  
  - Remote Syslog
  - Loggly (HTTPS)
  - Loggly (JSON over Remote Syslog)  
- Improved the labels used in the Admin UI (some of them were a bit unclear).  
- Changed default engine of Database Log Table to InnoDB, which is more reliable and performing.

I also removed the licence files I added in the past, but such change should not have an impact, as you never used them to start with.