Bug 1042363

+++ This bug was initially created as a clone of Bug #1029493 +++

Description of problem:
Provisioning of RHEL7 virtual (KVM) guest on RHEL7 host fails with traceback because of missing python modules.

Version-Release number of selected component (if applicable):
Satellite: Satellite 5.6
host: RHEL-7.0-20131111.1 Server x86_64
      rhn-virtualization-common-5.4.34-4.el7.noarch
      rhn-virtualization-host-5.4.34-4.el7.noarch

How reproducible:
always

Steps to Reproduce:
1. sync RHEL7 channel to Satellite
2. register RHEL7 to the Satellite, add Virtualization entitlement
3. create RHEL7 virtual kickstart
4. schedule provisioning of RHEL7 virtual guest on registered RHEL7 host
5. on RHEL7 host run `rhn_check -vvv`
6. check the output

Actual results:
D: handle_action actionid = 41, version = 2
D: do_call kickstart_guest.initiate('<RHEL7 host>', '<satellite>:1:<virt-guest>', 'qemu', 10, '<virt-guest>', 512, 1, 3, 'virbr0', '/var/lib/libvirt/images/<virt-guest>', ' '){'cache_only': None}
- looking for Cobbler at http://<RHEL7 host>/cobbler_api
- reading URL: http://ib<RHEL7 host>/cblr/svc/op/ks/system/<satellite>:1:<virt-guest>
install_tree: http://<RHEL7 host>/ty/MbMww5qC
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/koan/app.py", line 1185, in load_virt_modules
    import xencreate
  File "/usr/lib/python2.7/site-packages/koan/xencreate.py", line 35, in <module>
    import virtinst
ImportError: No module named virtinst
no virtualization support available, install python-virtinst?
D: Sending back response(1, 'Virtual kickstart failed. Koan error.', {'koan': 'no virtualization support available, install python-virtinst?'})
D: do_call packages.checkNeedUpdate('rhnsd=1',){}

Expected results:
RHEL7 KVM virtual guest is provisioned properly

Additional info:
looking into RHEL7 tree, there's no python-virtinst package (in RHEL7 base channel), while in RHEL5/6 the package is included in base channel