[css-text] Clarify handling of zero-width tabs per Xidorn's suggestion. Fix w3c#460.

Author: fantasai

css-text/Overview.bs

@@ -680,7 +680,8 @@ Languages and Typesetting</h4>
     <ol>
       <li>A sequence of collapsible spaces at the beginning of a line is
         removed.
-      <li>Each tab is rendered as a horizontal shift
+      <li>If the tab size is zero, tabs are not rendered.
+        Otherwise, each tab is rendered as a horizontal shift
         that lines up the start edge of the next glyph with the next <a>tab stop</a>.
         <dfn lt="tab stop">Tab stops</dfn> occur at points that are multiples of the tab size
         from the block's starting content edge.
@@ -2270,7 +2271,8 @@ Acknowledgements</h2>
   Laurie Anna Edlund, Ben Errez, Yaniv Feinberg, Arye Gittelman, Ian
   Hickson, Martin Heijdra, Richard Ishida, Masayasu Ishikawa,
   Michael Jochimsen, Eric LeVine, Ambrose Li, Håkon Wium Lie, Chris Lilley,
-  Ken Lunde, Nat McCully, IM Mincheol, Shinyu Murakami, Paul Nelson, Chris Pratley, Marcin Sawicki,
+  Ken Lunde, Nat McCully, IM Mincheol, Shinyu Murakami, Paul Nelson,
+  Chris Pratley, Xidorn Quan Marcin Sawicki,
   Arnold Schrijver, Rahul Sonnad, Alan Stearns, Michel Suignard, Takao Suzuki,
   Frank Tang, Chris Thrasher, Etan Wexler, Chris Wilson, Masafumi Yabe
   and Steve Zilles.

css-text/issues-lc-2013.html

@@ -1000,6 +1000,16 @@ <h1>CSS Text Level 3 Disposition of Comments for 2013-10-10 LCWD</h1>
 <span>From:     fantasai</span>
 <span>Comment:  <a href='https://www.w3.org/mid/544892F8.2070703@inkedblade.net'>https://www.w3.org/mid/544892F8.2070703@inkedblade.net</a></span>
 <span>Open</span></pre>
+<pre class=' a' id='issue-118'>
+<span>Issue 118. <a href='#issue-118'>#</a></span>
+<span>Summary:  Clarify handling of zero-sized tabs</span>
+<span>From:     Koji Ishii</span>
+<span>Comment:  <a href='https://github.com/w3c/csswg-drafts/issues/460'>https://github.com/w3c/csswg-drafts/issues/460</a></span>
+<span>Response: <a href='https://github.com/w3c/csswg-drafts/issues/460#issuecomment-246245920'>https://github.com/w3c/csswg-drafts/issues/460#issuecomment-246245920</a></span>
+<span class="a">Closed:   Accepted</span>
+<span class="a">Verified: <a href='https://github.com/w3c/csswg-drafts/issues/460#issuecomment-247266948'>https://github.com/w3c/csswg-drafts/issues/460#issuecomment-247266948</a></span>
+<span>Resolved: <a href='https://www.w3.org/mid/CADhPm3sFBf3bUMwQUBx96C5F2Y0T0bETneSRc9MGpGqw5Yu3vg@mail.gmail.com'>https://www.w3.org/mid/CADhPm3sFBf3bUMwQUBx96C5F2Y0T0bETneSRc9MGpGqw5Yu3vg@mail.gmail.com</a></span>
+<span>----</span></pre>
 <script>
 (function () {
 	var sheet = document.styleSheets[0];

css-text/issues-lc-2013.txt

@@ -979,3 +979,12 @@ From:     fantasai
 Comment:  https://www.w3.org/mid/544892F8.2070703@inkedblade.net
 Open
 ----
+Issue 118.
+Summary:  Clarify handling of zero-sized tabs
+From:     Koji Ishii
+Comment:  https://github.com/w3c/csswg-drafts/issues/460
+Response: https://github.com/w3c/csswg-drafts/issues/460#issuecomment-246245920
+Closed:   Accepted
+Verified: https://github.com/w3c/csswg-drafts/issues/460#issuecomment-247266948
+Resolved: https://www.w3.org/mid/CADhPm3sFBf3bUMwQUBx96C5F2Y0T0bETneSRc9MGpGqw5Yu3vg@mail.gmail.com
+----