new structure in revised README
added test for storage pickling
refactored pickle everywhere but Session, removed unused imports
Merge pull request #491 from niphlod/fix/readme

new structure in revised README
Merge pull request #492 from niphlod/tests/storage_pickling

added test for storage pickling
Merge pull request #493 from niphlod/fix/refactoring_pickle

refactored pickle everywhere but Session, removed unused imports
fixed pickling of session
fixed is_crypt in tools, thanks Anthony