Fix XSS vulnerabilities

Use {paramName:htmlEncode} in Sencha's HTML templates to prevent XSS
exploits.
Fix XSS vulnerabilities

Use Ext.util.Format.htmlEncode for user generated content in Sencha's
html property to prevent XSS exploits.
Fix XSS vulnerabilities

Use Ext.util.Format.htmlEncode for user generated content assigned to
Sencha's text property (the text property does not filter HTML by
itself!) used in session lists to prevent XSS exploits.
Fix XSS vulnerabilities

Use Ext.util.Format.htmlEncode for user generated content used by
Ext.data.JsonStore grouper's groupFn to prevent XSS exploits.