Create imports.json

Added the HTML Imports API
Create custom-elements.json

Added the Custom Elements API
Merge pull request #628 from cletusw/htmlImports

Create imports.json
Merge pull request #629 from cletusw/customElements

Create custom-elements.json
data update
Update css-sticky.json

Position sticky will be available in firefox 32, not 31 (https://bugzilla.mozilla.org/show_bug.cgi?id=916315)
Added browser bug in IE 10
Add note of Chrome for iOS bug.
Fix bad grammar.
Merge pull request #631 from oscarotero/patch-1

Update css-sticky.json
Merge pull request #632 from hirechrismeyers/patch-1

Added background-size support bug in IE 10
Merge pull request #633 from anthonyryan1/master

CSP - Add known issue with Chrome for iOS
validate numbered notes
add missing comma
data update
remove test files
Add info on numbered notes
Update input-placeholder.json
data update
remove test files again
Merge pull request #635 from arleytriana/patch-3

Update known issues of input placeholder attribute