[IMP] Web: ListView: semantics classes for row decoration

based on bootstrap contextual colors, and bold/italic fonts.

Backward compatibility is ensured as the ListView is monkey-patched
to keep interpreting colors and fonts attributes.

addons/web/static/src/css/base.css

@@ -2555,6 +2555,12 @@
   height: 27px;
   border-top: 1px solid #ddd;
 }
+.openerp .oe_list_content > tbody > tr.text-bf {
+  font-weight: bold;
+}
+.openerp .oe_list_content > tbody > tr.text-it {
+  font-style: italic;
+}
 .openerp .oe_list_content > tbody > tr > td.oe_list_field_cell {
   padding: 3px 6px;
   white-space: pre-line;

addons/web/static/src/css/base.sass

@@ -2103,6 +2103,10 @@ $sheet-padding: 16px
             > tr
                 height: $row-height
                 border-top: 1px solid #ddd
+                &.text-bf
+                    font-weight: bold
+                &.text-it
+                    font-style: italic
                 > td.oe_list_field_cell
                     padding: 3px 6px
                     white-space: pre-line