Cigsegy

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- Support create a segy from a sub-volume array and a full volume segy header, using ``cigsegy.create_by_sharing_header('sub.segy', 'header-full.segy', dsub, iline=, xline=, istep=, xstep=, offset=)``
- Add a function ``Pysegy.cut(outsegy, ...)`` to cut a sub-volume from the full segy file and save to a segy file
- For all functions to create a segy file, you can use ``custom_info`` to custom the first 12 lines of textual header
- Support the segy files with inline first order, (i.e., the order is time->inline->crossline, the default is time->crossline->inline)
- Fixed a bug of ``scan()`` function
- Add a function ``tools.plot_region(...)`` to plot the region of a segy file

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- Add some useful functions, such as ``trace_count()``, ``get_traceInfo()``
- ``fromfile``, ``tofile``, ``create_by_sharing_header`` functions support ``istep`` and ``xstep`` parameters to deal with the segy whose steps of inline/crossline is not 1
- Add ``tools.guess`` function to guess the locations and steps of inline/crossline
- Add ``tools.fromfile_by_guess``, ``tools.tofile_by_guess``, ``create_by_sharing_header_guess`` to support unknown segy files
- Support windows/MSVC