Editorial: Fix title-casing in 6 clause titles.

spec.html

@@ -54,7 +54,7 @@ <h1>Conformance</h1>
 
 <!-- es6num="3" -->
 <emu-clause id="sec-normative-references">
-  <h1>Normative references</h1>
+  <h1>Normative References</h1>
   <p>The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.</p>
   <p>ISO/IEC 10646:2003: <i>Information Technology &ndash; Universal Multiple-Octet Coded Character Set (UCS) plus Amendment 1:2005, Amendment 2:2006, Amendment 3:2008, and Amendment 4:2008</i>, plus additional amendments and corrigenda, or successor</p>
   <p>ECMA-402, <i>ECMAScript 2015 Internationalization API Specification</i>.
@@ -123,7 +123,7 @@ <h1>The Strict Variant of ECMAScript</h1>
 
   <!-- es6num="4.3" -->
   <emu-clause id="sec-terms-and-definitions">
-    <h1>Terms and definitions</h1>
+    <h1>Terms and Definitions</h1>
     <p>For the purposes of this document, the following terms and definitions apply.</p>
 
     <!-- es6num="4.3.1" -->
@@ -12763,7 +12763,7 @@ <h1>Static Semantics: IsValidSimpleAssignmentTarget</h1>
 
     <!-- es6num="12.7.3" -->
     <emu-clause id="sec-addition-operator-plus">
-      <h1>The Addition operator ( `+` )</h1>
+      <h1>The Addition Operator ( `+` )</h1>
       <emu-note>
         <p>The addition operator either performs string concatenation or numeric addition.</p>
       </emu-note>
@@ -17266,7 +17266,7 @@ <h1>Runtime Semantics: Evaluation</h1>
 
   <!-- es6num="13.16" -->
   <emu-clause id="sec-debugger-statement">
-    <h1>The `debugger` statement</h1>
+    <h1>The `debugger` Statement</h1>
     <h2>Syntax</h2>
     <emu-grammar>
       DebuggerStatement :
@@ -25428,7 +25428,7 @@ <h1>Date Time String Format</h1>
 
         <!-- es6num="20.3.1.16.1" -->
         <emu-clause id="sec-extended-years">
-          <h1>Extended years</h1>
+          <h1>Extended Years</h1>
           <p>ECMAScript requires the ability to specify 6 digit years (extended years); approximately 285,426 years, either forward or backward, from 01 January, 1970 UTC. To represent years before 0 or after 9999, ISO 8601 permits the expansion of the year representation, but only by prior agreement between the sender and the receiver. In the simplified ECMAScript format such an expanded year representation shall have 2 extra year digits and is always prefixed with a + or - sign. The year 0 is considered positive and hence prefixed with a + sign.</p>
           <emu-note>
             <p>Examples of extended years:</p>
@@ -36677,7 +36677,7 @@ <h1>FunctionDeclarations in IfStatement Statement Clauses</h1>
 
     <!-- es6num="B.3.5" -->
     <emu-annex id="sec-variablestatements-in-catch-blocks">
-      <h1>VariableStatements in Catch blocks</h1>
+      <h1>VariableStatements in Catch Blocks</h1>
       <p>The content of subclause <emu-xref href="#sec-try-statement-static-semantics-early-errors"></emu-xref> is replaced with the following:</p>
       <emu-grammar>Catch : `catch` `(` CatchParameter `)` Block</emu-grammar>
       <ul>