Let mouse and touch events propagate upwards
Merge pull request #173 from PaulMougel/let-events-propagate

Let mouse and touch events propagate upwards. Closes #170.
Smart volume.display. Closes #174.
Merge pull request #175 from tsherif/volume-display

Smart volume.display. Closes #174.
Merge branch 'master' of https://github.com/aces/brainbrowser

Conflicts:
	src/brainbrowser/volume-viewer/lib/utils.js
	src/brainbrowser/volume-viewer/modules/loading.js