tarfile module fail to extract tarball with utf8 filenames when destination is an unicode
string. We need to convert dest as utf-8 string to restore an expected behaviour

=> Image debian-generic v4 loaded
Error: 'ascii' codec can't encode character u'\xe9' in position 27: ordinal not in range(128)
Traceback (most recent call last):
  File "/usr/bin/is", line 482, in <module>
    error(e)
  File "/usr/bin/is", line 480, in <module>
    args.func(p_main, args)
  File "/usr/bin/is", line 242, in c_list
    img, repo = select_image(o, repoman, args.best)
  File "/usr/bin/is", line 64, in select_image
    return repoman.get(image, version, best)
  File "/usr/lib/python2.6/dist-packages/installsystems/repository.py", line 616, in get
    return repo.get(name, version), repo
  File "/usr/lib/python2.6/dist-packages/installsystems/repository.py", line 399, in get
    pkg = PackageImage(path, fileobj=memfile, md5name=True)
  File "/usr/lib/python2.6/dist-packages/installsystems/image.py", line 458, in __init__
    arrow("Author: %s" % self.author, 1)
  File "/usr/lib/python2.6/dist-packages/installsystems/printer.py", line 107, in arrow
    out(" #light##yellow#=>#reset# %s" % message)
  File "/usr/lib/python2.6/dist-packages/installsystems/printer.py", line 55, in out
    fd.write("%s%s" % (message, endl))
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 27: ordinal not in range(128)

We need installsystems is functional on squeeze systems...

So we needs to embed:
- argparse 2.7.1 (not in python2.6)
- progressbar 2.3 (not in debian squeeze)

We can now use installsystems without paramiko

Add a changelog file inside isimage with a custom format which allow
image creator to quickly show update between images

Add a isversion field inside isimage which tell which version of installsystems was used to build image

Also fix some bug in PipeFile

This commit introduce remote repository and file accross ssh

currently db badly create if directory already exists before creation

We now use PipeFile to handle complex file type and compute md5 and filesize.

This commit add the following features in installsystems:
- A download progress bad
- check size before download
- check size after download
- check md5 after download

Signed-off-by: Seblu <sebastien.luttringer@smartjog.com>

Seblu: Fix too many things...

Signed-off-by: Seblu <sebastien.luttringer@smartjog.com>

$ is del description
Error: not a gzip file

$ is del description
Error: Unable to open image description: not a gzip file

best mode search best version across all repo and not the first