update to Ext JS 5.0.1

There were some issues with the proxy demo in v1.0.0 due to Ext JS 5.0.0 bugs that have been fixed in 5.0.1.
Changes in detail:
* switch to Ext JS 5.0.1
* rownumberer grid column is back
* use the new Sencha Charts package

The proxy demo is now again fully functional.