(*) MCShowerClusterViewer ... shows a full shower profile in 2D ... very fun :)
(*) Reflect ClusterViewerAlgo instance name on the canvas, so we can differentiate
(*) Adding MCShowerClusterViewer in test_merger.py (no mcshower? don't worry it will simply skip and won't crash nor add extra processing time)

Kazu
Merge branch 'trunk' of github.com:/larlight/LArLight into trunk