logic: Added update checker connecting to online API

* connects to https://www.sourcetrail.com/api/v1/versions/latest
* sends information about OS, platform, license type, current version and a unique user token
* Automatic update check is enabled via Startscreen and performed once every 24 hours on window focus
* Update check can be forced by clicking on "check for new version" on start screen
* renamed TimePoint to TimeStamp

fortune cookie message = In Träumen und im Leben ist nichts unmöglich.

src/lib/data/storage/StorageStats.h

@@ -1,7 +1,7 @@
 #ifndef STORAGE_STATS_H
 #define STORAGE_STATS_H
 
-#include "utility/TimePoint.h"
+#include "utility/TimeStamp.h"
 
 struct StorageStats
 {
@@ -20,7 +20,7 @@ struct StorageStats
 	size_t completedFileCount;
 	size_t fileLOCCount;
 
-	TimePoint timestamp;
+	TimeStamp timestamp;
 };
 
 #endif // STORAGE_STATS_H