Toggle .btn-edit-subj.open class

`$show-subject` true for external URIs only

src/main/webapp/static/com/atomgraph/linkeddatahub/css/bootstrap.css

@@ -51,7 +51,8 @@ li button.btn-edit-constructors, li button.btn-add-data, li button.btn-add-ontol
 .btn.dropdown-toggle.btn-acl { text-align: right; font-size: 0; color: transparent; background-image: url('../icons/baseline-remove_red_eye-24px.svg'); background-position: center center; background-repeat: no-repeat; width: 64px; }
 .btn.dropdown-toggle.btn-read { text-align: right; font-size: 0; color: transparent; background-image: url('../icons/ic_details_black_24px.svg'); background-position: center center; background-repeat: no-repeat; width: 64px; }
 .btn.btn-copy-uri { font-size: 0; color: transparent; background-image: url('../icons/content_copy-24px.svg'); background-position: center center; background-repeat: no-repeat; width: 48px; }
-.btn.btn-edit-subj { font-size: 0; color: transparent; background-image: url('../icons/expand_more_black_24dp.svg'); background-position: center center; background-repeat: no-repeat;  width: 48px; height: 30px; }
+.btn.btn-edit-subj { font-size: 0; color: transparent; background-image: url('../icons/baseline-expand_more-24px.svg'); background-position: center center; background-repeat: no-repeat;  width: 48px; height: 30px; }
+.btn.btn-edit-subj.open { background-image: url('../icons/baseline-expand_less-24px.svg'); }
 .btn.btn-save-as { font-size: 0; color: transparent; background-image: url('../icons/save_black_24dp.svg'); background-position: center center; background-repeat: no-repeat; width: 48px; }
 .btn.btn-skolemize { font-size: 0; color: transparent; background-image: url('../icons/link_black_24dp.svg'); background-position: center center; background-repeat: no-repeat; width: 48px; }
 .btn.btn-edit { font-size: 0; color: transparent; background-image: url('../icons/ic_create_black_24px.svg'); background-position: center center; background-repeat: no-repeat; width: 48px; padding-left: 0; padding-right: 0; }

src/main/webapp/static/com/atomgraph/linkeddatahub/xsl/bootstrap/2.3.2/client/form.xsl

@@ -343,6 +343,8 @@ WHERE
         <!-- subject .control group is the first one after <legend> -->
         <xsl:variable name="subj-control-group" select="ancestor::legend/following-sibling::div[1][contains-token(@class, 'control-group')]" as="element()"/>
 
+        <xsl:sequence select="ixsl:call(ixsl:get(., 'classList'), 'toggle', [ 'open' ])[current-date() lt xs:date('2000-01-01')]"/>
+
         <xsl:for-each select="$subj-control-group">
             <xsl:choose>
                 <xsl:when test="ixsl:style(.)?display = 'none'">