v0.5.2

Add "cool down" (seconds) && Allow to match BSSID for WiFi Event && Check permissions before enabling plugins && fixes & improvements

• Add "cool down" time (in seconds) for the re-activation of the same event
• WifiEventPlugin can now handle BSSIDs
  • If you need to match BSSID and ESSID, you will need two chained events
• Check (and require) permissions before enabling plugins in Settings
• Fix NfcEventPlugin (which wasn't really working previously)
• Code improvements
  • See 00fa3a6