Segyio

* seismic unix-style aliases are available for python in the segyio.su
namespace
* segyio has learned how to calculate the rotation of the cube
(segy_rotation_cw and segyio.tools.rotation)
* The python header objects behave more as dicts as expected
* The new program segyio-cath is added, a cat-like program that concatenate
text headers.
* Infrastructure improvements
* segyio for python is available via pypi (pip)
* segyio is now meant to be consumed with binary downloads of versions, but
with a rapid release cycle. Releases within a major release will be backwards
compatible
* Shared linking of the python extension is considered deprecated on Windows.

* Requirements for the shape of the right hand side of `f.trace[:] =`
expressions are relaxed and accepts more inputs
* C interface slightly cleaned up for C99 compliance
* C library can reason on arbitrary header words for offsets, not just 37

* Examples in the readme
* Delay recording time (t0) is interpreted as milliseconds, not microseconds
* Some minor optimisations
* segy_mmap is more exception safe
* The applications warn if mmap fails
* Support for static analysis with cppcheck
* The statoil/pycmake repo is used for python integration in cmake
* Minor milli/microsecond bugfixes in mex bindings
* tools.wrap added for printing textual headers to screen or file

* Float conversions (ibm <-> native) has been optimised and is much faster
* `segy_binheader_size` returns signed int like its friends
* `sample_interval` steps are now floats
* Multiple internal bug fixes
* Some buffer leaks are plugged
* segyio has learned to deal with files without good geometry.
If `strict = False` is passed to segyio.open, and a file is without
well-sorted inlines/crosslines, open will return a file handle, but with
geometry-dependent modes disabled
* `file.samples` returns a list of samples, not number of samples
* Readme has been improved.
* `trace[int]` is more robust w.r.t. inputs
* A new mode has been added; gather. gather depends on a good geometry, and its
getitem `[il, xl, slice(offsets)]` returns all offsets for an
inline/crossline intersection

* segyio has learned to deal with large files (>4G) on more platforms
* segyio can read quickly attributes (trace header words) over the full file
* python can tell the fast and slow directions apart
* Reading depth slices is much faster
* tools.collect for gathering read samples into a single numpy ndarray
* tools.cube for easily reading a full cube
* tools.native for fast third-party segy-to-native float conversion
* File opening in binary mode is now enforced
* Data types have been overhauled (prefer signed integers)
* Enumerations have been SEGY prefixed to reduce collisions
* Building shared libs can be switched on/off on cmake invocation
* Makefiles and CI overhauls

* Matlab has learned about prestack files
* Reading traces in matlab no longer fails when not reading the whole file
* Matlab argument keys have been renamed