- This migrates the current systemvmtemplate build system from
veewee/virtualbox to packer and qemu based.
- This also introduces and updates a CentOS7 built-in template.
- Remove old appliance build scripts and files.
- Adds iftop package (CLOUDSTACK-9785)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>