'Analog Window Trigger condition type' C getter / setter / resetter can't be called because the function name is incorrect

[dratinyy]

According to the NI-DAQmx C Reference, functions to call when accessing the Analog Window Trigger condition are:

• DAQmxGetAnlgWinStartTrigWhen
• DAQmxSetAnlgWinStartTrigWhen
• DAQmxResetAnlgWinStartTrigWhen

as opposed to what can be found in nidaqmx/_task_modules/triggering/start_trigger.py (lines 1036, 1052, 1065), which end with 'StartTrigTrigWhen'.

I'm not adding extra information such as Python version and such since this is more of a mistake rather than a bug. Also I can confirm updating the function names will have them work as intended.

[rares-pop]

Addressing this in #93.