data/ovirt_vms: Export IP configurations of VM

[imjoey]

Signed-off-by: imjoey [email protected]

Issue #172 .

Changes proposed in this pull request:

• Make the IP addresses exportable by adding new reported_devices attribute
• Add acceptance testings for new attribute
• Add missing docs for data source ovirt_vms

Output from acceptance testing:

$ make testacc TEST=./ovirt TESTARGS='-run=TestAccOvirtVMsDataSource_searchFilter'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./ovirt -v -run=TestAccOvirtVMsDataSource_searchFilter -timeout 180m
=== RUN   TestAccOvirtVMsDataSource_searchFilter
--- PASS: TestAccOvirtVMsDataSource_searchFilter (0.80s)
PASS
ok      github.com/ovirt/terraform-provider-ovirt/ovirt 0.834s