FlowEngine to support onclick, onfocus, events for the widget

[fyhao]

To allow FlowEngine's widget to register event such as onclick, onfocus, for client side events actions.

Ideas:

• to define textfield id, e.g. usernameTF then create new key other than flow, say usernameTF_onclick, then it contains a steps array as usual, the step will be executed upon the textfield is being clicked.

Features:

• [x] onclick
• [x] onchange

Backlog Tasks:

• [x] Remove www folder

Test script:

Test script successfully tested onclick and onchange flow. 'params' => array( array('type' => 'label','name'=>'test','id'=>'log'), array('type' => 'text', 'name' => 'username'), array('type' => 'text', 'name' => 'textbtn'), ) , 'events' => array( 'textbtn_onclick' => 'username_click_flow', 'username_onchange' => 'username_change_flow' ) , 'username_click_flow' => array( 'steps' => array( array('type' => 'setValue', 'name' => 'textbtn','value'=>'click'), ) ) , 'username_change_flow' => array( 'steps' => array( array('type' => 'setValue', 'name' => 'textbtn','value'=>'change'), ) )

After feature done, trigger client validation issue

[fyhao]

Working on this in branch dev