Backport imgcreate to RHEL5 pykickstart

Backport imgcreate to RHEL5 pykickstart

RHEL5 pykickstart differs from latest Fedora pykickstart
in quite a number of ways:

  - No commands, errors or version sub-modules, but there
    is a data sub-module

  - readKickstart() doesn't support relative includes
    very well; it only tries the paths relative to the
    current directory rather than relative to the directory
    the topmost kickstart is in

  - Most of the parsed data is available at KsParser.ksdata
    rather than KsParser.hander.foo

  - No support for group include types (i.e. required, default,
    all etc.)

  - The contents of ksdata.groupList are a simply groups names
    rather than Group objects

  - ksdata.device has the following format:

      <type> <module>[:<module>...] [--opts=<opts>]

    rather than being a Device object.

  - No bootloader timeout or default kernel options.

  - No includepkgs/excludepkgs repo options.

  - Some ksdata attributes - e.g. timezone, firewall, rootpw,
    etc. - are dicts rather than objects

Signed-off-by: Mark McLoughlin <markmc@redhat.com>