Version 1.5.3

1.5.3

• segyio-catr has learned to handle no arguments, and as a results read the
  first trace header as intended
• segyio-catr has its help text and man page corrected
• segyio-crop has learned to say how many traces it copies
• segyio-crop has learned to warn when no traces are copied
• segyio-crop has learned not to overwrite its input file when source and dest
  is the same
• The makefiles understand the BUILD_DOC option, to build the python docs with
  sphinx
• Test suite has some speed and robustness improvements