Add SPF.

SPF is a lightweight JS framework for fast navigation and page updates from
YouTube.  The code is from https://github.com/youtube/spfjs.  This is v2.0.0,
the initial major distribution release.
Added handsontable plugins

These were present in previous releases -- e.g., /files/jquery.handsontable/0.11.2/extensions/
Update snowplow.js to 2.1.2 with 'curl --compressed http://d1fc8wv8zag5ca.cloudfront.net/2.1.2/sp.js'
Update project tappy to 0.3.1
Update project tauCharts to 0.1.19
Merge pull request #2590 from jsdelivrbot/tappy/0.3.1

Update project tappy to 0.3.1
Merge pull request #2591 from jsdelivrbot/tauCharts/0.1.19

Update project tauCharts to 0.1.19
Merge pull request #2559 from apeckham/master

Update snowplow.js to 2.1.2
Merge pull request #2566 from nicksay/add-spf

Add SPF.
Merge pull request #2587 from paulo-raca/handsontable-0.12-extensions

Added handsontable extensions for version 0.12.