TrangaTask now only contains essentials, derived classes contain specific information such as connectorName, publication, chapter, etc.
Removed taskQueue system, instead all tasks are kept in _allTasks.
Progress is being tracked in TrangaTask resolves #36 resolves #32
Added new TrangaTask: DownloadChapter to download single chapters. #35
Fixed duplicate file-access when writing settings.
TrangaTask is now abstract
TrangaTask implements Execute Method, that is now called instead of TaskExecutor
Created inheriting classes of TrangaTask: UpdateKomgaLibraryTask, DownloadNewChaptersTask