Preferences Update

• Added a preferences window that replaces seldom used menu items and surfaces advanced and experimental preferences
• You can now set the default activation duration for the menu bar icon in preferences
• Removed the advanced preference for info.marcel-dierkes.KeepingYouAwake.PreventSleepOnACPower
• Added an advanced preference to allow display sleep while still preventing system sleep (Issue #25)
• Ability to set a battery level on MacBooks where the app will deactivate itself (Issue #24)
  • Thank you timbru31 for the suggestion!
• Upgraded to Sparkle 1.14.0 to fix potential security issues