Credits to Aurelien Dunand

Thanks to Aurelien Dunand

Arrow is now relative this allow to pass context of arrow
no more verbose mode. Soft is verbose except in quiet mode

Script is now compiled before execution to have a better debugging features.
local directory is no more given for each scripts
global directory is new to each script execution
only namespace object must be used to share data across scripts

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

Can be removed when min default will be python 2.7

New module tools offer functions to base is class and also to setup scripts.
Drop RepositoryBase class.