Added controls for the COMP_QUE fields in the Config Register that handle the Comparator output. Also added an example of use.

Added comments for new functions

Added threshold properties, changed to "comparator_queue_length" property name, added "convert to voltage" and "convert to value" functions

Writing of the threshold registers moved to the setter functions, "threshold" spelled out in variables, improved readability of some comments.

Fixed issues in ads1x15 init comment. Removed stray copy/paste and added more info for comparator thresholds.

Disabled instance attributes req for ADS1x15 init function and shortened "possible_comparator_queue_lengths" to "possible_comp_queue_lengths"

Trying to fix "too many instance attributes" issue

Threshold properties changed to 12-bit signed integers and conversion to unsigned 16-bit numbers moved to threshold setter functions.

Adapted functions to use bits properties and moved part specific settings to subclasses

Moved specific comments about threshold registers to subclasses

Conversion calculations handled with signed integers, removing 2s complement. Removed subclass comparator threshold defaults since both chips have same default values.