Fixed bug with not opening the editor when clicking a file from the file browser. Implemented watching the file on disk. * MainWindow: Simplified opening file request calls. * FileEditor: Added new slot that closes tabs without and index and made FileEditorTabs connect to it. * FileEditorTab: Added QFileSystemWatcher and fixed bug with setting modified status on m_modified. Implemented message boxes for the cases that a file has been removed, renamed und modified from outside.