Comment 6 for bug 1271177

Changed bug statuses to reflect:

a) 5.6 has the bug, in that SHOW must block there, currently it
doesn't.

b) Any client willing to get non-causal output when a global
wsrep-causal-reads is set (a global value of wsrep-causal-reads may not
be advisable but that is a different topic) should use session value of
wsrep-causal-reads=0.

c) b applies to backup tools too.

d) There is one another 'bug' here in that starting a new mysql client also
seemed to block. Need to investigate that.

e) If b doesn't work out, then use causal_read_timeout galera
variable in wsrep-provider-options