Add storage_capacity_mb parameter to broker

This sets the maximum amount of space to be allocated to instances by
the broker
[#71061560]
Remove max_db_per_node limit since the broker no longer uses it

[#72110750]
Added HAProxy in front of mySQL cluster

 * HAProxy has new ip address
 * Broker points to HAProxy ip
 * Added HAProxy user to mySql
 * Syslogging not correcly configured

[#71510170]
Rolling restart of mySQL nodes

[#71510170]
Uploading / syncing new blobs

[#71510170]