This commit adds a test case for Xtrabackup involving SST Basically, . it starts two servers, does a Xtrabackup SST between them and finally . checks for galera co-ordinates in the xtrabackup_galera_info file and . matches it with that in the server .
Few other things fixed include:
a) Correct prefix for galera library.
b) Added a special condition to common.sh to avoid mysql_install_db.