seperate test concerns by model

* merge in the latest project-management branch PR #141
* seperated concerns out of features/step_definitions/common.rb into
         features/step_definitions/project_steps.rb
         features/step_definitions/tips_steps.rb
         features/step_definitions/user_steps.rb
* merged features/step_definitions/web.rb into
         features/step_definitions/common.rb
* merged features/step_definitions/tip_modifier_interface.rb into
         features/step_definitions/tips_steps.rb