docs: fix testing instructions for installed build
fix number of returned values for no refinement in refine_reference()
fix make_l2_projection_data() for parameter variables
update nodal_stress() to accept user-provided integrals
new examples/linear_elasticity/its2D_interactive.py
fix path in script/gen_lobatto1d_c.py

- bug introduced in ec186b8c69b0719f483e11a864092a21a608a203
clean up script/edit_identifiers.py
fix sys.path in auxiliary scripts and standalone examples

- for cases where the current directory (i.e. top level sfepy directory) is not
  added automatically
simplify probes, use pyVTK library
Primer - use VTK probes
new postrocessing function base on VTK, example
docs: add interactive example section to primer
Merge branch 'master' of github.com:BubuLK/sfepy into 1D
update User's guide - postrocessing filters
Merge pull request #276 from vlukes/post_vtk
fix get_vtk_from_mesh(), remove temporary file
update test_install.py for current linear_elastic_probes.py
prevent modifying linear_elastic.py namespace in derived examples
new tests/test_input_linear_elastic_probes.py
Merge branch 'its-interactive-example'