addModulePath method and some fixes

1. `addModulePath` defines conrete path for module lookup
e.g. addModulePath( "QtQuick.Controls","http://someserver.com/controls"
) will force system to `import QtQuick.Controls` module from
`http://someserver.com/controls/qmldir`

2. Added conversion from dot-notation to slash-notation in imports
loading.

src/qtcore.js

@@ -867,25 +867,38 @@ QMLEngine = function (element, options) {
             // resolve name from relative to full dir path
             // we hope all dirs are relative
             name = this.removeDotSegments( currentFileDir + name );
-            if (name[ name.length-1 ] == "/") name = name.substr( 0, name.length-1 ); // remove trailing slash as it required for `readQmlDir` 
+            if (name[ name.length-1 ] == "/") 
+              name = name.substr( 0, name.length-1 ); // remove trailing slash as it required for `readQmlDir` 
         }
         // TODO if nameIsDir, we have also to add `name` to importPathList() for current component...
 
         // check if we have already loaded that qmldir file
         if (engine.qmldirsContents[ name ]) continue;
 
         var content = false; 
-        var probableDirs = [""];
-			  // nameIsUrl => url do not need dirs    
-			  // nameIsDir => already computed full path
-
-        if (nameIsQualifiedModuleName) 
-          probableDirs = [currentFileDir].concat( engine.importPathList() )
+
+        if (nameIsQualifiedModuleName && this.userAddedModulePaths && this.userAddedModulePaths[ name ]) {
+          // 1. we have qualified module and user had configured path for that module with engine.addModulePath
+          content = readQmlDir( this.userAddedModulePaths[ name ] );
+        } 
+        else if (nameIsUrl || nameIsDir) 
+        {
+          // 2. direct load
+   			  // nameIsUrl => url do not need dirs    
+  			  // nameIsDir => already computed full path above
+          content = readQmlDir( name );
+        }
+        else
+        {
+          // 3. qt-style lookup for qualified module
+          var probableDirs = [currentFileDir].concat( engine.importPathList() ) 
+          var diredName = name.replace( /\./g,"/" );
 
-        for (var k=0; k<probableDirs.length; k++) {
-          var file = probableDirs[k] + name;
-          content = readQmlDir( file );
-          if (content) break;
+          for (var k=0; k<probableDirs.length; k++) {
+            var file = probableDirs[k] + diredName;
+            content = readQmlDir( file );
+            if (content) break;
+          }
         }
 
         if (!content) { 
@@ -977,6 +990,21 @@ QMLEngine = function (element, options) {
     this.importPathList = function() {
       return (this.userAddedImportPaths || []);
     }
+
+    // `addModulePath` defines conrete path for module lookup
+    // e.g. addModulePath( "QtQuick.Controls","http://someserver.com/controls" )
+    // will force system to `import QtQuick.Controls` module from `http://someserver.com/controls/qmldir`
+
+    this.addModulePath = function( moduleName, dirPath ) {
+
+      // remove trailing slash as it required for `readQmlDir` 
+      if (dirPath[ dirPath.length-1 ] == "/") 
+          dirPath = dirPath.substr( 0, dirPath.length-1 ); 
+
+      // keep the mapping. It will be used in loadImports() function .
+      if (!this.userAddedModulePaths) this.userAddedModulePaths = {};
+      this.userAddedModulePaths[ moduleName ] = dirPath;
+    }
 
     this.$registerStart = function(f)
     {