v5.0

Main changes:

• Clock synchronization can be performed manually from the config menu.
• Added a 5 seconds delay before synchronization-on-boot, to avoid temporary network errors.
• Safer cancellation of background threads, to reduce the chance for memory leaks.
• Background threads are now limited to a max of 4.
• Default clock drift tolerance was increased to 1 second.
• Configuration file now stores time values with their units (minutes, seconds, milliseconds).

Full Changelog: v4.2...v5.0