If not, global_dict.update(self.modules) raise an exception (TypeError:
NoneType) if lib dir is missing.

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

c_install function are moved to image

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

This patch review how scripts are executed and modules loaded.

sys.module is preserved from modification by scripts and avoid conflict with
module loaded by scripts

Only support pure python module in lib/, package (like foo.bar) don't work.

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

ISException is an Installsystems exception which can handle an exception and
his information (type, value, traceback).

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

With the permission of Romain Degez, CTO of Smartjog and Sébastien Luttringer.

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

We use current locale to convert argv to unicode and handle it as uncode after.

If we have to format (aka interpolatation) we need to be sure this have to be
done in unicode and not in ascii. This avoid unicode error with ascii string
encoded in utf-8.

Example of failure between a string and an object

b = Exception(u"é")
Exception("error: %s" % b)
 => Exception("error: %s" % str(b)
 => UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 0: ordinal not in range(128)

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

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

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

In case of bad download, error given by is feeder is better than output
of compressor which claims data are missing

We now use system tar and gzip to compress/decompress payloads

Goals are:
- Speed-up extraction and creation of payloads.
- Allow to use non-python supported compressor like (pbzip2 and xz)
- Remove python2.7.1 tarfile.py module
- Remove python 2.7.1 gzip.py to avoid filename to be in gzip headers
- Remove gzipstream.py module used to stream gzip file

also optimize tarball.getnames

build -p recreate payload file if already exsits

is build now create payloads without version in name and create symplink with version to it.

This is very useful to avoid too many recreation of payload after adding to db or when bumping version