Add help content support for C/C++ editor preference pages

doc/org.eclipse.cdt.doc.user/help.css

@@ -82,3 +82,15 @@ th.valign-top, td.valign-top { vertical-align: top }
 th.valign-bottom, td.valign-bottom { vertical-align: bottom }
 th.valign-middle, td.valign-middle { vertical-align: middle }
 div.listingblock pre { padding: 0.7em }
+.admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
+.admonitionblock>table td.icon{text-align:center;width:80px}
+.admonitionblock>table td.icon img{max-width:initial}
+.admonitionblock>table td.icon .title{font-weight:bold;text-transform:uppercase}
+.admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #ddddd8}
+.admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
+.admonitionblock td.icon [class^="fa icon-"]{font-size:2.5em;text-shadow:1px 1px 2px rgba(0,0,0,.5);cursor:default}
+.admonitionblock td.icon .icon-note:before{content:"\f05a";color:#19407c}
+.admonitionblock td.icon .icon-tip:before{content:"\f0eb";text-shadow:1px 1px 2px rgba(155,155,0,.8);color:#111}
+.admonitionblock td.icon .icon-warning:before{content:"\f071";color:#bf6900}
+.admonitionblock td.icon .icon-caution:before{content:"\f06d";color:#bf3400}
+.admonitionblock td.icon .icon-important:before{content:"\f06a";color:#bf0000}

doc/org.eclipse.cdt.doc.user/topics_Reference.xml

@@ -92,7 +92,9 @@
 			<topic label="Templates" href="reference/cdt_u_code_temp.htm"/>
 			<topic label="Typing" href="reference/cdt_u_c_editor_typing.htm"/>
 		</topic>
-
+
+		<anchor id="cdt_Preferences_Anchor"/>
+
 		<topic label="File Types" href="reference/cdt_u_c_file_types.htm"/>
 		<topic label="Indexer" href="reference/cdt_u_indexer_preference.html"/>
 		<topic label="Language Mappings" href="reference/cdt_u_language_mapping_pref.htm"/>