support local cdroms

Local cdroms can now be added directly to the domain. See the
following example:

```hcl
resource "libvirt_domain" "test-domain" {
    name = "test"

    disk {
	file = "path/to/file.iso"
    }
}
```

Furthermore, a small Tiny Core Linux (TCL) ISO image has been added to
the testdata. This can be used for testing purposes.

Signed-off-by: Thomas Hipp <thipp@suse.de>

1 files changed, 0 insertions, 0 deletions

diff --git a/libvirt/testdata/tcl.iso b/libvirt/testdata/tcl.iso
new file mode 100644
index 00000000..303088d0
--- /dev/null
+++ b/libvirt/testdata/tcl.iso