Setters and Getters methods were created for GroupData class

Setters and Getters methods were created for GroupData class.
Corresponding methods were created for all fields: name, header, footer.
Setters and Getters methods were created for ContactData class

Setters and Getters methods were created for ContactData class.
Corresponding methods were created for all fields in class.
Group and Contact creation, modification, removal methods were modified to chain approach.

Group and Contact creation, modification, removal methods were modified
to chain approach. ContactHelper and GroupHelper were modified.
Group and Navigation methods were modified

Group and Navigation methods were modified. New creation method was
added to GroupHelper class.
GroupModificationTests and GroupRemovalTests were modified

GroupModificationTests and GroupRemovalTests were modified.  Some high
levels methods were created in GroupHelper.
Contact tests were modified

Contact tests were modified. Additional metods createContac,
modifyContact,, deleteContact were created. ContactHelper class was
modified by adding new methods.