Added logic and test for case without terminal (eg. Jenkins)

Gruntfile.js

@@ -47,8 +47,13 @@ module.exports = function(grunt)
     grunt.loadNpmTasks('grunt-contrib-jshint');
     grunt.loadNpmTasks('grunt-contrib-clean');
     grunt.loadNpmTasks('grunt-contrib-nodeunit');
+
+    grunt.registerTask('unset_clearline', 'Unset stdout.clearLine for testing', function(){
+        process.stdout.clearLine = undefined;
+    });
 
     grunt.registerTask('test', ['clean', 'svg2png', 'nodeunit']);
+    grunt.registerTask('test_noterminal', ['unset_clearline', 'test']);
     grunt.registerTask('default', ['jshint', 'test']);
 
 };

tasks/svg2png.js

@@ -79,10 +79,14 @@ module.exports = function(grunt)
             if (!total) {
                 return;
             }
-
-            process.stdout.clearLine();
-            process.stdout.cursorTo(0);
-
+
+            var hasTerminal = !!process.stdout.clearLine;
+
+            if (hasTerminal) { 
+                process.stdout.clearLine();
+                process.stdout.cursorTo(0);
+            }
+
             var str = style('0%', 'yellow') + ' [ ',
                 arr = [],
                 count = total,
@@ -93,7 +97,8 @@ module.exports = function(grunt)
             }
             str += arr.reverse().join('');
             str += ' ] ' + style(percent + "%", 'green') + ' (' + ((new Date() - start) / 1000).toFixed(1) + 's) ';
-            process.stdout.write(str);
+
+            process.stdout.write(str + (hasTerminal ? '' : "\n"));
         };
 
         var spawn = grunt.util.spawn({