Description of problem:
At the moment it is possible to clone a VM template to multiple Storage Domains. When creating a VM from template using the API without specifying the storage domain, it will be implicitly stored on the original Storage Domain where the template was created. This RFE is to enable storage load balancing when creating VMs from templates, so that the least used SD (in free space percentage) is selected to provision the VM when no destination SD is selected explicitly and template is copied to multiple SDs

Version-Release number of selected component (if applicable):
3.4.1

How reproducible:
Always

Steps to Reproduce:
1. create VM template on SD1
2. clone template to SD2
3. create VM using the API without specifying the destination SD

Actual results:
VM disks always placed on SD1

Expected results:
VM disks created on the SD with more free space at the moment