Nidaqmx

* Resolved Issues
* [32: Incorrect types in samp_quant_samp_per_chan and total_samp_per_chan_generated parameters](https://github.com/ni/nidaqmx-python/issues/32)
* [1: nidaqmx doesn't work on Python 2.7.13](https://github.com/ni/nidaqmx-python/issues/1)

* Resolved Issues
* Adding lock around `argtypes` to prevent race condition between setting `argtypes` and calling functions, in cases
the functions run in parallel.
* Some special cases needed unconditional locks around both the setting of `argtypes` and the actual function call,
like the variadic power-up state functions in system.py, and the register events functions in task.py.

* Merged Pull Requests
* [Fix for unregistering callbacks](https://github.com/ni/nidaqmx-python/pull/15)
* Resolved Issues
* [13: Should _import_lib error for unsupported platforms?](https://github.com/ni/nidaqmx-python/issues/13)
* [12: Cannot catch load/version issues with public API](https://github.com/ni/nidaqmx-python/issues/12)
* [11: CONTRIBUTING.rst link to Issues is broken](https://github.com/ni/nidaqmx-python/issues/11)

* Initial public release of nidaqmx
* Update setup.py description and fix issues 2, 3, 5, and 6 raised by Ed Page.
* Splitting joined acronyms AIADC, AIDC, AILVDT, AIRVDT and CITC.
* Adding link to LICENSE file.
* Updating README.rst file in source directory to eliminate Sphinx domaindirectives and add link to documentation on
readthedocs.

* Initial pre-release of nidaqmx