feat(facsimile): add question marks for uncertainty

scenarios/xslt/edxml2html/css/styles.css

@@ -326,6 +326,13 @@ hr.metamark-line.doubleLine {
 }
 
 /*::::::::::::::::::::::::::::::::::{ TEI: Transcriptional }::::::::::::::::::::::::::::::::*/
+
+.g[data-cert="uncertain"]:after {
+  content: "?";  
+  font-size: small;
+  vertical-align: super;
+}
+
 .surface .tei::before,
 .surface .tei::after {
     color: brown;

scenarios/xslt/edxml2html/libs/html-facsimile.lib.xsl

@@ -64,13 +64,21 @@
     
     
     <!-- LINE-PARTS -->
-    <xsl:template match="g">
+    <xsl:template match="g[not(@cert)]">        
         <span class="g" 
             id="{if(@xml:id) then (@xml:id) else ('part_'||generate-id(.))}">
             <xsl:apply-templates/>
         </span>    
     </xsl:template>
     
+    <xsl:template match="g[@cert]">        
+        <span class="g"
+            data-cert="{@cert}"
+            id="{if(@xml:id) then (@xml:id) else ('part_'||generate-id(.))}">
+            <xsl:apply-templates/>
+        </span>    
+    </xsl:template>
+    
     <xsl:template match="metamark[contains(@rend, 'Line') or contains(@rend, 'line')]">
         <xsl:variable name="rend" select="@rend"/>
         <hr class="metamark-line {$rend}" data-rend="{$rend}"/>