Replace EqDataBase by FieldSet

- remove EqDataBase class
- move some code to FieldSet, namely ADD_FIELD macro and add_field method
  in order to keep current field specifications in equations
- cleanup in field.*; make_input_tree is protected,
  keep only get_input_type in interface
- merge bc_data and bulk_data lists in all equations
- use derive EqData classes in equations from FieldSet
  make appropriate adjustments
- adjust unit_Tests/coupling/
- merge bc_data and bulk_data in tests 01,02,03
Merge branch 'JB_unsteady_darcy' of github.com:flow123d/flow123d into JB_unsteady_darcy