This commit adds automation that will reduce the possibility
of user errors when customizing wsrep_notify.sh (in particular
caused by user-specified parameters). Now all leading and trailing
spaces are removed from the user-specified parameters and automatic
port and host address substitution has been added to scripts, as
well as automatic password substitution to the client command line,
only if it is specified in the wsrep_notify.sh and not as empty
strings. Also added support for automatic substitution of the all
SSL-related parameters and improved parsing for ipv6 addresses
(to allow "[...]" notation for ipv6 addresses). Also added a
test to check if the wsrep notify script will works with SSL.