CHANGE: http://review.gluster.com/2868 (cli: More xml output changes) merged in master by Vijay Bellur (vijay)

Appending '--xml' to a quota command will produce xml output. Tested on v3.3.0qa44.

Eg:

-!- ~ » gluster volume quota test enable --xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<cliOutput><opRet>0</opRet><opErrno>9</opErrno><opErrstr>Enabling quota has been successful</opErrstr><cliOp>volQuota</cliOp><output>Enabling quota has been successful</output></cliOutput>

-!- ~ » gluster volume quota test limit-usage /test 100MB
limit set on /test

-!- ~ » gluster volume quota test limit-usage /test2 10MB --xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<cliOutput><opRet>0</opRet><opErrno>2</opErrno><opErrstr>limit set on /test2</opErrstr><cliOp>volQuota</cliOp><output>limit set on /test2</output></cliOutput>

-!- ~ » gluster volume quota test list --xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<cliOutput><opRet>0</opRet><opErrno>0</opErrno><opErrstr></opErrstr><volQuota><quota><path>/test</path><limit>100MB</limit><size>0</size></quota><quota><path>/test2</path><limit>10MBB</limit><size>0</size></quota></volQuota></cliOutput>

-!- ~ »