Added colors to issue list icons

Corrected icon for warnings
Made disconnected_highway issue a warning instead of an error

modules/ui/issues.js

@@ -149,12 +149,12 @@ export function uiIssues(context) {
         var label = enter
             .append('label');
 
-        label
-            .call(
-                svgIcon(function(d) {
-                    var iconSuffix = d.severity === 'warning' ? 'alert' : 'error';
-                    return '#iD-icon-'+iconSuffix;
-                }, 'pre-text'));
+        label.each(function(d) {
+            var iconSuffix = d.severity === 'warning' ? 'alert' : 'error';
+            d3_select(this)
+                .call(svgIcon('#iD-icon-' + iconSuffix, 'pre-text'));
+        });
+
         /*label
             .append('input')
             .attr('type', type)

modules/validations/disconnected_highway.js

@@ -46,7 +46,7 @@ export function validationDisconnectedHighway(context) {
 
                 issues.push(new validationIssue({
                     type: ValidationIssueType.disconnected_highway,
-                    severity: ValidationIssueSeverity.error,
+                    severity: ValidationIssueSeverity.warning,
                     message: t('validations.disconnected_highway', {entityLabel: entityLabel}),
                     tooltip: t('validations.disconnected_highway_tooltip'),
                     entities: [entity],