Rename all plugins
Begin to fix building script
Fix : Fix package name and test if cloned repository is empty
Merge pull request #18 from savoirfairelinux/toto

Fix building scripts
Enh: New ShinkenPlugin base class.

+ Moved STATES to own module for easy reuse.
+ custom PluginParser for customized exit().
+ better add_threshold() functions.
+ helpers with parsing methods for "size" amounts (MB|KB|..).
+ included argparse if one doesn't wants to install it from system packages.