Only execute dpms test when we can

- Add test-runner.js to be able to execute the dpms when these
  conditions are complied:
     1 - DPMS extension is supported.
     2 - DPMS version is 1.1.
     3 - DPMS is capable.

package.json

@@ -20,7 +20,7 @@
     "should": "*"
   }
 , "scripts": {
-    "test": "mocha -t 80000",
+    "test": "node test-runner.js",
     "prepublish" : "npm prune"
   }
 }

test-runner.js

@@ -0,0 +1,58 @@
+var x11 = require('./lib/x11');
+var Mocha = require('mocha');
+var fs = require('fs');
+var path = require('path');
+var util = require('util');
+
+var mocha = new Mocha({
+	timeout : 80000
+});
+
+// To be able to perform the tests we need the server:
+// 1 - to support the dpms extension.
+// 2 - dpms version is 1.1.
+// 3 - to be dpms capable.
+var run_dpms_test = function(cb) {
+    var client = x11.createClient(function(dpy) {
+        var display = dpy;
+        var X = display.client;
+        X.require('dpms', function(ext) {
+            if (!util.isError(ext)) {
+                dpms = ext;
+                dpms.GetVersion(undefined, undefined, function(err, version) {
+                    if (!err && version[0] === 1 && version[1] === 1) {
+                        dpms.Capable(function(err, capable) {
+                            if (!err && capable[0] == 1) cb(true);
+                            else cb(false);
+                        });
+                    } else {
+                        cb(false);
+                    }
+                });
+            } else {
+                cb(false);
+            }
+        });
+    });
+
+    client.on('error', function() {
+        cb(false);
+    });
+};
+
+// Add all files from test root directory
+fs.readdirSync('./test').forEach(function(file) {
+	if (file === 'dpms.js') {
+		run_dpms_test(function(run) {
+			if (run) {
+				mocha.addFile(path.join('./test', file));
+			}
+
+			mocha.run(function(){
+				process.exit();
+			});			
+		});
+	} else {
+		mocha.addFile(path.join('./test', file));
+	}
+});

test/dpms.js

@@ -11,23 +11,12 @@ describe('DPMS extension', function() {
         var client = x11.createClient(function(dpy) {
             display = dpy;
             X = display.client;
-            // To be able to perform the tests we need the server:
-            // 1 - to support the dpms extension.
-            // 2 - dpms version is 1.1.
-            // 3 - to be dpms capable.
             X.require('dpms', function(ext) {
                 if (util.isError(ext)) {
                     done(ext);
                 } else {
                     dpms = ext;
-                    dpms.GetVersion(undefined, undefined, function(err, version) {
+                    done();
-                        if (err) return done(err);
-                        version.should.eql([1, 1]);
-                        dpms.Capable(function(err, capable) {
-                            if (!err) capable.should.eql([1]);
-                            done(err);
-                        });
-                    });
                 }
             });
         });