Update to linux-create-upload-vhd

- Fix bug in step 6 for CentOS and Oracle
- Other minor formatting fixes
Merge pull request #1771 from szarkos/linux-upload-a-vhd

Update to linux-create-upload-vhd
Merge remote-tracking branch 'upstream/master' into linux-configure-raid

* upstream/master:
  Update to linux-create-upload-vhd