signUp and signIn implmentation, and refactorings.
    User: Added sessionToken;

    implementation of insertMethod, with filling of sessionToken and
    updateDate.
Changes in User registration

* Global: Use of User.include instead User.save
* Users: Remotion of password confirmation; verification of username
repetition transferred to User Model
* User: insert method replaced by inlcude; Verification of username
repetition .
* Formatters: dateFormatter extracted from JsonFormatter
* UserSpec: Testing User.include
Added BCrypt library, and implmented the help function for hashing password.
Finished the unittest of Algorithms. But still have unknown bugs.
Changes for Mock tests. Users.singUp as PUT

See http://stackoverflow.com/questions/10053424/mock-objects-in-play2-0
* models.User: Trait UserModel exteracted from Object model to enable
Mocking.
* controllers.Users: Abstract class UsersController extracted from
controllers.Users to enable injection of UserModel  in Unit Tests. Key
Constants extractd to Key Object (at least temporarily).
* routes: Call to signUp changed from POST to PUT. reindentation;
* Build.scala: Added reference to mockito library
* UsersSayHelloSpec: Trying to mock but without success
* UserControllersTest: Added to mock UserModel behevior.
Spec tests for UsersControllers.getOneById
Fixed unit test of utils.AlgorithmsSpec.scala
Spec tests for controllers.UsersController.signUp.

More adjusts.
Spec tests for controllers.UserController.singIn

Refactoring in UserController.singIn and singUp: pre-verification user
data request .
Spec Tests for controllers.UserController.findAll

models.UserModel: UserModel.findAll functionality replaced by
userModeU.findAllUsers to use List instead SalatMongoCursor and
facilitate mocking.
Merge remote-tracking branch 'origin/master'
* UserModel: It was converted to a trait with just methods declaration, with no bind with ModelCompanion. Object User extends both UserModel as ModelCompanon. Objective is separate declaration from implementation and allow more isolated unit tests. Added methods to update and inactivate User.

* UserControllers: Added delete method. update will be implmented next.
* UsersControllersSpec: tests for UserControllers.delete. Extracion of verifyCorrectUser method.
UserModel.include return type changed to model.User

* models.User: UserModel.include throws exception in case of error.
* controllers.User: singUp handles with return type of UserModel.include

* UserSpec and UsersControllersSpec: changes relative to
UserModel.include changes.
models.User: More Spec Tests

Spec tests for findOneById, findOneByUsername and inactivate
route for user deletion
models.UserModel.findOneById replaced by findById

* models.UserModel: findOneById replaced by findById; It verifies if
User is active or not; default version returns just active Users.
* controllers.UsersControllers: call to UserModel.findOneById replaced
by UserModel.findById
* controllers.UsersControllersSpec: The same as UsersControllers
* models.UserSpec: tests for UserModel.findById
findOneByUsername verifies if user is active or not
findAllUsers verifies if Users are active or not

controller.userModel.findAllUsers return type converted to Iterator to
fit with SalatMongoCursor superclass) and verifies if Users are active
or not.
routes file rewritten to fit in REST API model

* controllers.Users: Added update method, but without real implmentation