Drop 'right' from the list of CSS settings

It is unused since commit 89e29b542c36378718382c1807e2a14fdbcdf16b.
Improve the wording for computed text position alignment

The text position alignment is always set, and the auto value is not
special in the same sense as for line and position.
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
Use the correct unit for the regions left offset
Merge pull request #108 from foolip/left-unit

Use the correct unit for the regions left offset
Merge pull request #106 from foolip/var-right

Drop 'right' from the list of CSS settings
Merge pull request #107 from foolip/computed-special-value-auto

Improve the wording for computed text position alignment
Add separate enums for lineAlign and positionAlign

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26016
Merge pull request #109 from foolip/align-enums

Add separate enums for lineAlign and positionAlign
Restore size clamping in rendering

https://www.w3.org/Bugs/Public/show_bug.cgi?id=25660

This was removed in commit 3d05e2e05c72b01404cf290bf07c7f0f367827a7.
Text direction (LRT/RTL) now has no effect on position, so the restored
text is somewhat simpler than the original.
Use positionAlign instead of align for maximum size

This currently does the right thing, but will likely need to be revised
after https://www.w3.org/Bugs/Public/show_bug.cgi?id=26020 is fixed.
Drop punctuation trailing "If ..." in switches

The original WebVTT spec and current HTML spec does not use this style,
and no punctuation is still more common in this file.
Remove trailing period after [CSSVALUES] reference
Merge pull request #110 from foolip/switch-if-colon

Drop punctuation trailing "If ..." in switches
Add a missing </p>
Merge pull request #112 from foolip/missing-p

Add a missing </p>
Merge pull request #111 from foolip/trailing-period

Remove trailing period after [CSSVALUES] reference
Merge pull request #105 from foolip/maximum-size

Restore size clamping in rendering
Merge pull request #100 from silviapfeiffer/snapToLinesPositioning

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