[rubis] (change:minor) Better handling of special operations BACK_SPECIAL_OP and EOS_SPECIAL_OP:
* removed use of dummy operation
* in case of EOS_SPECIAL_OP, we start a new session from the HOME_OP operation and creating a new user
[rubis] (change:minor) Restored logic to create a new user by means of atomic data structures; this is more flexible than the method used in the original RUBiS client which fixes the maximum number of new users to a hard-coded number.
[rubis] (change:minor) Update doc