FieldSet::make_output_field_selection() creates selection with description including units.
Merge branch 'output_master' of github.com:flow123d/flow123d into output_master
Updated output for reactions (input key 'output_fields', stream inherited from the parent equation).
- output_fields have default value, so implicitly the results are saved
- fix name of selection for Darcy flow output_fields
- fix description of output_fields selection's values
- updated test con files
Documentation reaction term introduction added.
Merge branch 'output_master' of https://github.com/flow123d/flow123d into PE-reactions-output
Record substances moved to SorptionBase (not needed in DualPorosity and chemistry).
Renaming fields in DualPorosity.
Merge branch 'output_master' of github.com:flow123d/flow123d into output_master
Renaming fields and others in Sorption.
Rename Reaction base class, introduce reaction_term.
Darcy flow output includes input fields of the equation.
+ fix of Selection::copy_values() - check for duplicity of key index
Merge branch 'output_master' of github.com:flow123d/flow123d into output_master
Renaming por_m to porosity.
Cleanup of standard output.
Mass balance temporary fix - works only without reaction term.
Fix ReactionTerm parallel outputs objects and inovate test03.

- fix setting initial condition in DualPorosity and Sorption
- fix parallel output objects in DualPorosity and Sorption
- test03 - replace old dualpor and sorption keys
Reference manual missing figures - forgot to add.
New reaction term introduced in all tests.
TOS - old reactions removed, old test(20,23) reference data removed.
Old fields and keys for dualpor and sorption in convection_transport removed.