add CSS3 image-orientation
add picture element data file
update spec url
update spec status. Looks like picture element is not an official spec by W3C. Somebody needs to review this commit
add demo link
add picture element support for IE. The spec url indicates that the implementation for IE is not there yet
The spec url indicates no information on implementation
update support for all the platforms. Almost all set to unknown
update keyword usage percentage
Update background-img-opts.json
Update background-img-opts.json

removed trailing "17"
Added 'Known Issue' to contentsecuritypolicy
Update viewport-units.json

Did not know where to add buggyfill description, added to title
Update viewport-units.json
WebVTT disabled in Firefox 29 and 30
Merge pull request #511 from sladex/patch-3

Update background-img-opts.json
Merge pull request #512 from mkurz/contentsecuritypolicy_fix

Added 'Known Issue' to contentsecuritypolicy for Internet Explorer
Merge pull request #513 from Forkest/patch-1

Update viewport-units.json
Merge pull request #515 from mpopp75/fx-webvtt

WebVTT disabled in Firefox 29 and 30
Updates Notes

I updated (i.e. pseudo-class) to (i.e. :pseudo-class) & (i.e. ::pseudo-class)