Improve error handling

[crnbaker]

The error handler in spectrum_wrapper/error_handler.py currently only contains the descriptions of a few frequently encountered errors. Other errors are raised only by their Spectrum API error codes, and must be looked up in the Spectrum documentation.

As more errors are encountered while spectrumdevice is used, those most likely to be encountered should be added to the error handler. This issue holds a list of those errors.

At some point, the whole error codes table from the spectrum documentation should probably be included in spectrumdevice as a lookup table.

• ERR_NETWORKTRANSFER (0x00000041) The network data transfer from/to a digitizerNETBOX has failed