Squashed 'reveal.js/' changes from 784fa9d..cf8708f

cf8708f adjust copyright years
8a2f146 remove experimental tileflip transition, reduce max size of media content to 95% to account for slide padding
6b0fff3 enable backgrounds images when printing to pdf (closes #271)
11fc906 helper method for retrieving slide based on index (closes #293)
080fb3c disable zoom plugin while in overview mode
c21e6bb fix vertical centering of slide in ios chrome (closes #289)
2629be6 trailing ws
9b83013 fix error with removal of control button and progress bar event listeners (closes #323)
d182235 code cosmetics
abf9ddb Merge pull request #322 from commadelimited/deactivate-nav-during-pause
f45d948 describing new presentation sizing logic in readme
98a9908 fix word breaks in headers (closes #321)
c50ae08 remove extra padding in stacks, add api method to retrieve curren scale (#310)
723bd1c reduce width of single-page fallback slides
f0b93d8 Only allowing 'unpause' keyboard events while paused
1b01a74 change default maxScale to 1.0 (#310)
f7a0cf7 add config vars for #310 to readme
9660cdb add min/max scale settings (#310)
1ca8306 rename padding config option to margin, better mobile support for scaled presentations (#310)
a20d3b6 fix layering issue of anchors in ff with page transition (closes #274)
312eafe feature detect zoom with fallback on transform, allow percent units for deck width/height (#310)
d1c7452 updated to v2.3, initial implementation of uniformly scaled presentations (#310)

git-subtree-dir: reveal.js
git-subtree-split: cf8708f932fe7ba79186f37dd9a8ea94625b5bc4
Merge commit '8a114fd4839d217640fbece7cdd54bfa1a0af15a' into gh-pages
Squashed 'reveal.js/' changes from cf8708f..8c2be2f

8c2be2f find correct path to open html file from the notes.js path

git-subtree-dir: reveal.js
git-subtree-split: 8c2be2fdd73c64ea446b488ea3427cce84242905
Merge commit 'd954670a82d1ff0ef4882709637c9506d0ff12e6' into gh-pages