Remove re-positioning of boxes on snap-to-lines

Boxes are already positioned with x-position and y-position calculation
in step 8 when snapt-to-lines is true.
Closes https://www.w3.org/Bugs/Public/show_bug.cgi?id=19178
Merge pull request #100 from silviapfeiffer/snapToLinesPositioning

Remove re-positioning of boxes on snap-to-lines
Moving the respec menu underneath the bug filing.

This avoids overlap of these two boxes during spec development.
Merge pull request #114 from silviapfeiffer/moveRespecBugs

Moving the respec menu underneath the bug filing.
Add a conformance section.

Closes https://www.w3.org/Bugs/Public/show_bug.cgi?id=22591
Define WebVTT cue identifiers as unique.

Closes https://www.w3.org/Bugs/Public/show_bug.cgi?id=24674.
WebVTT region identifier must also be unique.
Merge pull request #113 from silviapfeiffer/uniqueIdentifier

Unique identifier
Merge pull request #115 from silviapfeiffer/conformanceSection

Add a conformance section.
Merge commit '5bbf1eacac1791fb2ff8f50c837d22f2e522156f' into position-size-align