ENH: Added colour param to plot_events
STY: fixed typo.
changed ev_idx to ev_mask
FIX: implemented cycle on colours
FIX: substituted next with zip in enumerate
ENH: added event_id and legend
ENH: event_id and colour dictionaries implemented, and legend
ENH: refactored event_id, colour and legend handling
ENH: tests + working event/color combinations.
ENH: code improvements.
reinstated warning
ENH: added event_id/color checks + example.
ENH: ylim scales with event_id values
sorted out logic for input dictionaries
fixed check against existing events
Modified check of event_id against existing events.
Code simplified.
Replaced for loop in event_id check
Added some comments.
Fixed event_id check; added comments.