rename sfepy/mechanics/contact_planes.py -> sfepy/mechanics/contact_bodies.py
new sfepy/linalg/check_derivatives.py - new check_fx()
use max-norm in check_fx()
new check_vfvx()
new ContactSphere
fix empty array condition in ContactPlaneTerm.smooth_f()
new ContactPlaneTerm._get_force_pars(), update .get_fargs()
new ContactSphereTerm (dw_contact_sphere)
new examples/linear_elasticity/elastic_contact_sphere.py + test
update HypermeshAsciiMeshIO reader: support for quad4 and tri3 cells
update mesh reading/writing: print infromation about supported cell types
script/save_basis.py: fix mesh mode, make permutations directly from mesh
script/plot_mesh.py: fix help message
generalize dict_to_array() for nD arrays
fix type errors under Windows: in nm.take() cells -> nm.int32(cells)
remove unused argument
fix get_facet_dof_permutations(), H1NodalMixin._setup_facet_orientations()

- permutations should come from facet nodes in reference order
- fixes #205
increase approximation orders of 3_4, 3_8 in tests/test_poly_spaces.py
prevent building ori_map for higher order elements in FESurface.__init__()
Merge branch 'fix_nodal_basis' - closes #205