PRESTO v3.0.1

• This is a minor release which fixes several issues and adds some
  minor improvements:
  • Fix of long-standing rfifind bug that could cause the program
    to hang if channels had zero variance
  • Multiple Python3-related bug fixes
  • Added -debug flag to prepfold to allow debugging of TEMPO
    calls to make polycos
  • DDplan.py can now read observation parameters from filterbank
    or PSRFITS input files. And you can write a dedisp_*.py
    dedispersion script, based on the plan, using the -w option
  • The rednoise program now writes a corresponding *_red.inf file
  • Update of the Tutorial document, including a new slide on red noise