libwebsockets

lws_button: classification

Now there's an abstract button class regardless of the underlying
connection, we can add more sophicsticated analysis on top of it
for processing its usually noisy events and classifying them into
smd-ready click, long-click or double-click events.

A "regime" defines the timing limits for different press recognition
and can be specified per-button, if not given a default regime is
applied.