remove invoke in SourcesCli.errors and fix Sources.get_all regex
Merge pull request #4 from matthieu-foucault/fix/sources-errors

remove invoke in SourcesCli.errors and fix Sources.get_all regex
improved doc.
fixed name of rc file.
added id in source hashes.
fixed extensions.
improved join. no samples and gathers files in each cluster.
added mongo as a dependency.
now ensure that plugins are subclasses of plugin classes.
bumped version.
refactored say_status methods in Utils.