Documentation: "Internal storage" description was updated.
problem::flags: new flags + documentation.
repository::is_available() bug fix + repository::is_available_() implementation.
include/bacs/archive/flags.hpp -> include/bacs/archive/problem/flags.hpp.
config refactoring + repository integration with bunsan::pm::repository.
repository integration with problem::validate_{id,flag}().
repository::is_{locked,read_only}() implementation.
repository: helper functions implementation.

{read,write}_{binary,hash,info}() and compute_hash().
ename::{hash,info,flags} declaration.
repository: m_problem_archiver -> m_problem_archiver_factory.
repository::insert() implementation.
repository::extract() implementation.
repository::existing() implementation.
repository::available() implementation.
repository::exists() implementation.
repository::status() implementation.
repository documentation was updated.
repository::set_flag{,s}() implementation.
repository documentation was updated.
repository::unset_flag{,s}() implementation.