[piernik_setup] some echo implementations don't understand -e switch
Merge pull request #100 from Xarthisius/master

[piernik_setup] some echo implementations don't understand -e switch
Add 'sgpt' to default hdf5 fields. Use correct code2cgs factor for gravitational potential written to gdf
Merge pull request #101 from Xarthisius/sgpt_hdf5

Add 'sgpt' to default hdf5 fields.
Fix all python scipts' shebangs
Merge pull request #102 from Xarthisius/python_shebang

Fix all python scipts' shebangs