server/static/base.js: add transitioner keyboard events

fullscreen mode can now be navigated with left and right arrows and
paused with spacebar ;)
server/static: default to blocks view, pause indicator, more refactoring
Merge branch 'upstream-master'
static/base.js: change pause key to down arrow
Merge pull request #36 from binar-e/master

server/static/base.js: add transitioner keyboard events, refactor