added less v 2.7.1, removed unused resources

apps/documenteditor/main/index.html

@@ -257,7 +257,7 @@
 
     <!-- debug begin -->
     <script type="text/javascript">var less=less||{};less.env='development';</script>
-    <script src="../../../vendor/less/dist/less-1.5.1.js" type="text/javascript"></script>
+    <script src="../../../vendor/less/dist/less-2.7.1.js" type="text/javascript"></script>
     <!-- debug end -->
 
     <script type="text/javascript" src="../../../vendor/jquery/jquery.min.js"></script>

apps/presentationeditor/main/index.html

@@ -265,7 +265,7 @@
 	
     <!-- debug begin -->
     <script type="text/javascript">var less=less||{};less.env='development';</script>
-    <script src="../../../vendor/less/dist/less-1.5.1.js" type="text/javascript"></script>
+    <script src="../../../vendor/less/dist/less-2.7.1.js" type="text/javascript"></script>
     <!-- debug end -->
 
     <script type="text/javascript" src="../sdk_dev_scripts.js"></script>

apps/spreadsheeteditor/main/index.html

@@ -264,7 +264,7 @@
 	
     <!-- debug begin -->
     <script type="text/javascript">var less=less||{};less.env='development';</script>
-    <script src="../../../vendor/less/dist/less-1.5.1.js" type="text/javascript"></script>
+    <script src="../../../vendor/less/dist/less-2.7.1.js" type="text/javascript"></script>
     <!-- debug end -->
 
     <script type="text/javascript" src="../../../vendor/jquery/jquery.min.js"></script>