Add XML file to import static files instead of the __openerp__.py file, it fits Odoo v8.0

web_digital_sign/__openerp__.py

@@ -31,15 +31,9 @@
         This module provides the functionality to store digital signature image for a record.
         The example can be seen into the User's form view where we have added a test field under signature.
     """,
-    'data': ['users_view.xml'],
-    'js':[
-          "static/lib/excanvas.js",
-          "static/lib/jquery.signature.js",
-          "static/src/js/digital_sign.js",
-    ],
-    'css':[
-        "static/src/css/digital.css",
-        "static/src/css/jquery.signature.css",
+    'data': [
+        'views/we_digital_sign_view.xml',
+        'users_view.xml'
     ],
     'website': 'http://www.serpentcs.com',
     'qweb': ['static/src/xml/digital_sign.xml'],

web_digital_sign/views/we_digital_sign_view.xml

@@ -0,0 +1,13 @@
+<openerp>
+    <data>
+        <template id="sale_order_backend" name="sale_order assets" inherit_id="web.assets_backend">
+            <xpath expr="." position="inside">
+                <link rel="stylesheet" href="/web_digital_sign/static/src/css/digital.css"/>
+                <link rel="stylesheet" href="/web_digital_sign/static/src/css/jquery.signature.css"/>
+                <script type="text/javascript" src="/web_digital_sign/static/lib/excanvas.js"></script>
+                <script type="text/javascript" src="/web_digital_sign/static/lib/jquery.signature.js"></script>
+                <script type="text/javascript" src="/web_digital_sign/static/src/js/digital_sign.js"></script>
+            </xpath>
+        </template>
+    </data>
+</openerp>