v0.1.0, 11-April-2016 -- Initial release
v0.1.1, 11-April-2016 -- Package info updated
v0.1.2, 11-April-2016 -- Documentation link corrected
v0.1.3, 12-April-2016 -- Relative links fixed
v0.1.4, 12-April-2016 -- Try to get a good setup.py working
v0.1.5, 13-April-2016 -- imu.data_import, and corresponding tests, fixed
v0.1.6, 13-April-2016 -- input from XIO-sensors added
v0.2.0, 13-April-2016 -- Data viewer works also for 3D data
v0.2.1, 13-April-2016 -- viewer termination fixed
v0.2.2, 15-April-2016 -- small fixes
v0.2.3, 01-May-2016 -- created new dir "sensors"
v0.2.4, 01-May-2016 -- "sensors" subpackage added to distribution
v0.2.5, 01-May-2016 -- fixed pathproblem for subpackage
v0.2.6, 15-May-2016 -- sensortype "polulu" added
v0.2.7, 15-May-2016 -- tests updated
v0.2.8, 23-May-2016 -- paths adjusted for Mac-compatability, docu added
v0.2.9, 31-Oct-2016 -- path for "sensors" added, docu adjusted
v0.2.10, 04-Nov-2016 -- fixed error with Python 2.x in imus.py
v0.3.0, 11-Nov-2016 -- "viewer.py" renamed to "view.py"; animated orientation visualization added
v0.3.1, 11-Nov-2016 -- type in quat.py fixed ("to.lower()"
v0.3.2, 11-Nov-2016 -- Fixed error in "__init__.py"
v0.3.3, 11-Nov-2016 -- Substantially updated "setup.py", removed version.py
v0.3.4, 12-Nov-2016 -- skipped (mistake)
v0.3.5, 12-Nov-2016 -- Switched to wheels
v0.3.6, 14-Nov-2016 -- Fixed the crash of "view.ts" with Python 2.x
v0.3.7, 14-Nov-2016 -- ... and another two bugs in "view" that got eliminated ...
v0.4.0, 11-June-2017 -- Switched to a more consistent naming convention
v0.4.1, 11-June-2017 -- Fixed Error in rotmat.sequence(R, to='Euler')
v0.4.2, 16-June-2017 -- Fixed Error in rotmat.sequence(R, to='Helmholz'); added deprecation info for "vel2quat"
v0.4.3, 25-June-2017 -- eliminated easygui, because it kept crashing on OSX (i.e. Macs)
v0.4.4, 17-July-2017 -- erroneous variable "type" eliminated in imus.import_data
v0.4.5, 08-Aug-2017 -- make functions in "vector" also work with list input; adjust names to Python standards
v0.4.6, 27-Aug-2017 -- made function names in "imus.py" more consistent/clear
v0.5.0, 04-Sep-2017 -- Introduced an abstract class in "imus.py"
v0.5.2, 25-Sep-2017 -- Fixed import problem in "xsens.py" (only in standalone)
v0.5.3, 25-Sep-2017 -- Modified "setup.py", in order not to re-build existing scipy etc.
v0.5.4, 25-Sep-2017 -- Modified "setup.py" again ...
v0.6.0, 28-Oct-2017 -- sequence adjusted to match rotation matrices, quat2seq and seq2quat added
v0.6.1, 01-Dec-2017 -- Function "target2orient" added to "vector.py"
v0.6.2, 01-Dec-2017 -- Docu updated.
v0.6.3, 04-Dec-2017 -- "deprecetions" eliminated, "source" set in "sensors"
v0.6.4, 18-Dec-2017 -- implemented manual data input to IMU-objects. Fixed a few bugs.
v0.6.5, 18-Dec-2017 -- Documentation updated
v0.6.6, 18-Dec-2017 -- Sequence in "analytical" reverted.
v0.6.7, 18-Dec-2017 -- imus.analytical made more stable, by going from Rmats to quats
v0.6.8, 20-Dec-2017 -- Fixes a relative-path problem in the sub-package "sensors"
v0.6.9, 21-Dec-2017 -- Position calculation added to IMU-objects by default
v0.7.0, 09-Jan-2018 -- view.Orientation_OGL added
v0.7.1, 29-Jan-2018 -- rotmat.STM and rotmat.STM_s added (spatial transformation matrix) 
v0.7.2, 29-Jan-2018 -- small improvement of rotmat.stm_s
