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

also optimize tarball.getnames

dangerous options are last one

prepare and uprepare chroot functions now track non existant files
preparing are now done more carrefully about tricks

repo command can now purge cache of database

python-argparse (1.1) shipped with debian squeeze is bugged and doesn't work with installsystems needs
python-argparse 1.2.1 (last upstream version) was backported into squeeze and we need it.

Thanks to Antoine "Naps" Millet for its precisous help

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

a bug occur with string like "#l##c#R#R#".
This is due to order of processing colors.
Now use re.sub

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

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

* tricks /etc/mtab
* new output