We will eventually remove the delivery of the number of occurred signals
to the recipient. There haven't been any convincing use cases for this
feature. In the contrary, it actually led to wrong design choices in the
past where the rate of signals carried information (such as the progress
of time) that should better be obtained via an explicit RPC call.
The old 'Signal_rpc_member' template retains the old interface for now.
But the new 'Signal_handler' omits the 'unsigned' argument from the
handler function.
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