Support tracking of binary executables, improved NFS performance and signal handling

• Both, kernel-module and fanotify-backend now support tracking of binary executables
• Commands entered via the shell-integration are now less affected by busy NFS-storages due to lockless-reading of shournal's config file. Database-transactions now deal with busy-timeouts by not failing on first attempt.
• Improved signal handling in critical sections, in the shell integration as well as in the observation backends