This method returns a sysprep object with a given name. Now,
(enable,disable)_sysprep work with sysprep objects instead of sysprep
names

The do_sysprep method was not updated to comply with the changes
made in list_syspreps method

Populate Sysprep entry in "Image Customization Menu". Not fully
working.

This method takes a sysprep object as argument and returns the name
and a description for this object.

The method used to return 2 lists of enabled and disabled sysprep
object. Since sysprep objs contail an `enabled' attribute, it is easy
to determine which of those are enabled and which are not. There is
no need to return 2 seperate lists.

This dir will host help files used by snf-image-create-dialog

Image properties manipulation works fine.

Extract and Register menu entries work fine.

Otherwise the registration may fail.

If no customization is to be applied the image should be mounted
readonly.

Let the application decide what to do with them. If image-creator
receives an error from kamaki it will terminate. But this may not be
the proper thing to do for an interactive application like
image-creator-dialog

snf-image-creator-dialog is a dialog based version of snf-image-creator
Nothing works yet

Add an option to DiskDevice's mount method to allow readonly mount

The error function main.py used for outputing errors has been removed
and the code was not updated to use the error method of SimpleOutput
output class.
Also did a minor cleanup: git_os_class function was renamed to os_cls

In older versions of libguestfs, the recovery process did not close
the file descriptors it inherited. This could case problems if the
parent process had open pipes.

This is handy because now progress class can print using the output
methods of it's output class

If not then don't output progressbars and colors

The progress bar of the progress generator had a wrong max attribute.

All image-creator components now output messages using an instance
of one of the output classes.

The metadata are collected in the constructor and are saved in the
meta variable. This way they can be accessed and altered by the
sysprep methods. There are cases where some metadata are not valid
and need to be updated after a sysprep action is performed. For
example, remove_user_accounts sysprep action may remove a user that
is present in the USERS metadata.

The metadata passed by the user will overwrite any automatically
collected metadata with the same key.

This action will remove the swap entry from the fstab.

If the swap partition is the last partition in the media, then it can
be safely removed. The image-creator will save enough info in the
SWAP metadata to recreate it.

This is needed because otherwise setup.py fails on some systems. Also
do some more cleanup.

Not all needed code parts where updated when the size() method in
DiskDevice class was abandoned in favor of the size attribute.