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

--no-sync as the same beneficts

if no filter given, list in all online repository
Also remove list -S, can be done by is -s ''

also use Repository.is_repository_name to validatage repository name

This commmit make a big cleaning inside IS binary, moving all code insides functions
and removing unecessary use of variables

dangerous options are last one

repo command can now purge cache of database

list -S only list images inside searchable repositories

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

this allow a better display of images setup options and arguments

repo have now -s and -u option
new display and color

this state can be matched by option -l and -r in repo command

build -p recreate payload file if already exsits

this option allow list of image without syncing database. Very useful for completion

is list command now only list image inside repositories.
many option can be given to have a custom output
globbing is allowed on images

all options have now a long mode
some options name have changed

This command allow a clean listing of repositories

argparse is available in python2.7 (archlinux) and on python-argparse package in debian. So
we add a dependency to this package.

new option --preserve, -p is added

info command is used to get information about an image. It will replace list command

this command is and helper to chroot inside payload mounting /{proc,sys,dev,dev/pts} fs
inside the chroot and disable daemon restart

as a corolary, invalid option are no more loaded

This allow displaying to be done without coloration