update AUTHORS
update Field.from_conf() to set field kind from region kind
update surface field syntax in examples
remove Term.has_integral, .itype, .raw_itype attributes (unused)
clean up sfepy/fem/variables.py, add module docstring
new Variables.get_dual_names()
clean up sfepy/fem/equations.py, add module docstring
new Equations.get_variable_dependencies()
new sfepy/base/resolve_deps.py - functions for resolving dependencies

- new get_nums(), solvable(), remove_known(), try_block(), resolve()
update tests/test_base.py: new test_resolve_deps()
fix Equations.get_variable_dependencies() - do not include parameter variables
new Equations.create_subequations()
new ProblemDefinition.create_subproblem()
new EquationSequenceSolver for stationary problems with an equation sequence

- new replace_virtuals()
new examples/thermo_elasticity/thermo_elasticity_ess.py + test
add custom view for thermo_elasticity_ess.py example to script/gen_gallery.py
fix typo in docstring
add custom view for elastic_contact_sphere.py example to script/gen_gallery.py
docs: sync module index of developer guide with current sources
clean up script/eval_tl_forms.py, update for current sympy