Synced xtrabackup SST fixes from Percona tree (as of PXC 5.6.24-25.11 release). This fixes/adresses the following LP bugs:

- LP1380697: wsrep_sst_xtrabackup-v2 doesn't stop when mysql is SIGKILLed. (full fix for this (as engineeered by Percona) requires Linux-specific patch that we don't carry, but keep xtrabackup scripts as close as possible)
  - LP1399134: Log the innobackupex/SST logs in SST to syslog if possible. (fixed)
  - LP1405668: Race condition between donor and joiner in PXB SST. (fixed)
  - LP1405985: Fail early if xtrabackup_checkkpoints is missing. (fixed)
  - LP1407599: wsrep_sst_xtrabackup-v2 script causes innobackupex to print a false positive stack trace into the log. (fixed)
  - LP1441762: IST Fails with SST script error. (fixed)
  - LP1451670: Fail when move-back fails in xtrabackup SST. (fixed)

scripts/wsrep_sst_common.sh

@@ -19,6 +19,8 @@
 set -u
 
 WSREP_SST_OPT_BYPASS=0
+WSREP_SST_OPT_BINLOG=""
+WSREP_SST_OPT_CONF_SUFFIX=""
 WSREP_SST_OPT_DATA=""
 WSREP_SST_OPT_AUTH=${WSREP_SST_OPT_AUTH:-}
 WSREP_SST_OPT_USER=${WSREP_SST_OPT_USER:-}
@@ -41,6 +43,10 @@ case "$1" in
         readonly WSREP_SST_OPT_CONF="$2"
         shift
         ;;
+    '--defaults-group-suffix')
+        WSREP_SST_OPT_CONF_SUFFIX="$2"
+        shift
+        ;;
     '--host')
         readonly WSREP_SST_OPT_HOST="$2"
         shift
@@ -77,6 +83,10 @@ case "$1" in
         readonly WSREP_SST_OPT_GTID="$2"
         shift
         ;;
+    '--binlog')
+        WSREP_SST_OPT_BINLOG="$2"
+        shift
+        ;;
     *) # must be command
        # usage
        # exit 1
@@ -85,6 +95,8 @@ esac
 shift
 done
 readonly WSREP_SST_OPT_BYPASS
+readonly WSREP_SST_OPT_BINLOG
+readonly WSREP_SST_OPT_CONF_SUFFIX
 
 # try to use my_print_defaults, mysql and mysqldump that come with the sources
 # (for MTR suite)