Pinty

----------------

- Add support for registering with matplotlib's unit handling
(Issue 317, thanks dopplershift)
- Add converters for matplotlib's unit support.
(Issue 317, thanks Ryan May)
- Fix unwanted side effects in auto dimensionality reduction.
(Issue 516, thanks Ben Loer)
- Allow dimensionality check for non Quantity arguments.
- Make Quantity and UnitContainer objects hashable.
(Issue 286, thanks Nevada Sanchez)
- Fix unit tests errors with numpy >=1.13.
(Issue 577, thanks cpascual)
- Avoid error in in-place exponentiation with numpy > 1.11.
(Issue 577, thanks cpascual)
- fix compatible units in context.
(thanks enrico)
- Added warning for unsupported ufunc.
(Issue 626, thanks kanhua)
- Improve IPython pretty printers.
(Issue 590, thanks tecki)
- Drop Support for Python 2.6, 3.0, 3.1 and 3.2.
(Issue 567)
- Prepare for deprecation announced in Python 3.7
(Issue 747, thanks Simon Willison)
- Added several new units and Systems
(Issues 749, 737, )
- Started experimental pandas support
(Issue 746 and others. Thanks andrewgsavage, znicholls and others)
- wraps and checks now supports kwargs and defaults.
(Issue 660, thanks jondoesntgit)

------------------

- Add support for datetime math.
(Issue 510, thanks robertd)
- Fixed _repr_html_ in Python 2.7.
(Issue 512)
- Implemented BaseRegistry.auto_reduce_dimensions.
(Issue 500, thanks robertd)
- Fixed dimension compatibility bug introduced on Registry refactoring
(Issue 523, thanks dalito)

----------------

- Refactored the Registry in multiple classes for better separation of concerns and clarity.
- Implemented support for defining multiple units per `define` call (one definition per line).
(Issue 462)
- In pow and ipow, allow array exponents (with len > 1) when base is dimensionless.
(Issue 483)
- Wraps now gets the canonical name of the unit when passed as string.
(Issue 468)
- NumPy exp and log keeps the type
(Issue 95)
- Implemented a function decorator to ensure that a context is active (with_context)
(Issue 465)
- Add warning when a System contains an unknown Group.
(Issue 472)
- Add conda-forge installation snippet.
(Issue 485, thanks stadelmanma)
- Properly support floor division and modulo.
(Issue 474, thanks tecki)
- Measurement Correlated variable fix.
(Issue 463, thanks tadhgmister)
- Implement degree sign handling.
(Issue 449, thanks iamthad)
- Change `UndefinedUnitError` to inherit from `AttributeError`
(Issue 480, thanks jhidding)
- Simplified travis for faster testing.
- Fixed order units in siunitx formatting.
(Issue 441)
- Changed Systems lister to return a list instead of frozenset.
(Issue 425, thanks GloriaVictis)
- Fixed issue with negative values in to_compact() method.
(Issue 443, thanks nowox)
- Improved defintions.
(Issues 448, thanks gdonval)
- Improved Parser to support capital "E" on scientific notation.
(Issue 390, thanks javenoneal)
- Make sure that prefixed units are defined on the registry when unpickling.
(Issue 405)
- Automatic unit names translation through babel.
(Issue 338, thanks alexbodn)
- Support pickling Unit objects.
(Issue 349)
- Add support for wavenumber/kayser in spectroscopy context.
(Issue 321, thanks gerritholl)
- Improved formatting.
(thanks endolith and others)
- Add support for inline comments in definitions file.
(Issue 366)
- Implement Unit.__deepcopy__.
(Issue 357, thanks noahl)
- Allow changing shape for Quantities with numpy arrays.
(Issue 344, thanks tecki)

------------------
- Fixed backward incompatibility problem when parsing dimensionless units.

------------------

- Use NIST as source for most of the unit information.
- Added message to assertQuantityEqual.
- Added detection of circular dependencies in definitions.

----------------

- Added Systems and groups.
(Issue 215, 315)
- Implemented references for wraps decorator.
(Issue 195)
- Added check decorator to UnitRegistry.
(Issue 283, thanks kaidokert)
- Added compact conversion.
(See 224, thanks Ryan Dwyer)
- Added compact formating code.
(Issue 240)
- New Unit Class.
(thanks Matthieu Dartiailh)
- Refactor UnitRegistry.
(thanks Matthieu Dartiailh)
- Move definitions, errors, and converters into their own modules.
(thanks Matthieu Dartiailh)
- UnitsContainer is now immutable
(Issue 202, thanks Matthieu Dartiailh)
- New parser and evaluator.
(Issue 226, thanks Aaron Coleman)
- Added support for Unicode identifiers.
- Added m_as as way top retrieve the magnitude in different units.
(Issue 227)
- Added Short form for magnitude and units.
(Issue 234)
- Improved deepcopy.
(Issue 252, thanks Emilien Kofman)
- Improved testing infrastructure.
- Improved docs.
(thanks Ryan Dwyer, Martin Thoma, Andrea Zonca)
- Fixed short names on electron_volt and hartree.
- Fixed definitions of scruple and drachm.
(Issue 262, thanks takowl)
- Fixed troy ounce to 480 'grains'.
(thanks elifab)
- Added 'quad' as a unit of energy (= 10**15 Btu).
(thanks Ed Schofield)
- Added "hectare" as a supported unit of area and 'ha' as the symbol for hectare.
(thanks Ed Schofield)
- Added peak sun hour and Langley.
(thanks Ed Schofield)
- Added photometric units: lumen & lux.
(Issue 230, thanks janpipek)
- A fraction magnitude quantity is conserved
(Issue 323, thanks emilienkofman)
- Improved conversion performance by removing unnecessart try/except.
(Issue 251)
- Added to_tuple and from_tuple to facilitate serialization.
- Fixed support for NumPy 1.10 due to a change in the Default casting rule
(Issue 320)
- Infrastructure: Added doctesting.
- Infrastructure: Better way to specify exclude matrix in travis.