Ib-async

^^^^^^^^^^^^^^
* Fixed: :issue:`586`: Revert socket protocol back to version 176.

^^^^^^^^^^^^^^
* Potential fix for ``reqWshEventData``.

^^^^^^^^^^^^^^
* Added support for WSH (Wall Street Horizon) requests plus
the (blocking) convenience methods ``getWshMetaData`` and ``getWshEventData``.
* Updated socket protocol to version 177.
* Added support for ``Event`` security type.

^^^^^^^^^^^^^^

* Fixed: :issue:`534`: Session parsing for Forex contracts.
* Fixed: :issue:`536`: Handle empty session field.
* Fixed: :issue:`541`: Remove superfluous closing bracket.
* Fixed: :issue:`542`: Use float size for ``pnlSingle``.
* Fixed: :issue:`544`: Cancel head-time request after completion.
* Fixed: :issue:`545`: Return ``Trade`` instead of ``Order`` for
``reqOpenOrders`` and ``reqAllOpenOrders``.
* :pull:`553`: Volume bar added.
* :pull:`565`: Typo fix.

^^^^^^^^^^^^^^

* Add ``ContractDetails.tradingSessions()`` and
``ContractDetails.liquidSessions()`` to parse session times.
* Fix ``IBC.on2fatimeout`` command line argument for Unix.

^^^^^^^^^^^^^^

* Fix ``ib.reqMatchingSymbols`` to handle bond contracts.