updated particle data
;
correct setPos, get/setImage for gridshift
fixed typos
added box wrapping after origin shift
wrote unit test
renamed new test
correction to pdata to correct for shifted origin complete w/tests
Removed debug print statements
Merge pdata_gridshift_correct: fixes #3072

# By Benjamin Schultz (7) and Joshua A. Anderson (1)
* pdata_gridshift_correct:
  Removed debug print statements
  correction to pdata to correct for shifted origin complete w/tests
  renamed new test
  wrote unit test
  added box wrapping after origin shift
  fixed typos
  correct setPos, get/setImage for gridshift
  updated particle data ;