So far the wokrer used to sleep 10s and only check in those intervals
if [finally] a mapping had arrived. Using SIGMAPADD, we can
directly break the worker out of its select() call and hence make
it pick up a new mapping instantaneously.
This also makes RemsimBankd_Tests.TC_removeMapping_connected() pass
Change-Id: If0130ab4b49ffcae6ab7a8b9926a6d9477eb3981
Harald Welte
0fd77a5790