Added control action 'retry' to remove de necessity of sending local signal USR1 to flush retrier. This allows the web board to be ran on a different server

Fix: Since delegate constructor always returns, destructor is called when an exception is throws in constructor. Prevent destructor from executing on uninitialized object

Notifications ehancement : added notifications.tasks.concurrency and clearer logs + pass unix socket path to notification tasks for workflow analysis

Block signals to prevent msgrcv() and waitpid() from being interrupted. Signals are transmitted to the main thread.