Since the dmod and fmod setter take a string as argument and convert them to a
base 8 integer, we don't need to check and convert in integer with the
configobj validator.

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

configobj keeps the order of options in config file, we don't need to use
OrderedDict.

Seblu: Sad :'(

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

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>

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)

Before this, timeout only apply to repository caching.

Now timeout is used by all transfert functions.
A new parameter repo_timeout is available to set a custom timeout on repository

this options are also settable by config
allow to have installsystems niced before launch action

python-psutil minimun version is 0.2.1 to support set_ionice

old command line option are still present but no more in config file
this allow to override easily on command line config parameters

Image are not crawled anymore in all repositories by default
You needs to specify a list of repo to look in

as a corolary, invalid option are no more loaded

Concept of data was changed to payload.
Payload is not necessary a tarball of a file or a directory, but, directly a file without tarball around.
This is useful have the same md5 on data/payload and win some space during repo adding.
Now data which come with image are represented by class Payload and all operation are located inside. This is cleaner!
Payload also handle orginial information (mtime,uid,gid,md5,size,mode)

This changement require a lot of changement in Repository and RepositoryManager class

This commit change a lot of things in installsystems way of life.
Repository cache is now disabled on access to remote repository done directly.
New database and tarball format