TabbedPane does not validate non-selected tabs in server side tab switching mode (Relaed to TOMAHAWK-1012)

[Paul Spencer]

I use server side switching. Validation of non-selected tab would break 
many pages in my applications.  As an example, one of the applications 
allows the user to query a database.  Each tab is a specific type of 
query with it's own requirement,  i.e. "Start Time" and End Time" fields 
are required on the "Query by Time" and "SKU" is required on the "Query 
by "SKU" tab.  Forcing non-selected tab to pass validation would break 
this part of the application since many cases the required fields have 
no default value by design.

I can see a case where validation of non-selected tabs is need.  As an 
example, a series of tab that collect customer information where each 
tab is a type of information, "Name" "Billing Address"  "Shipping 
Address"....  Whether this should be implement as a 
"validateNonSelectedTab" attribute on <t:panelTabbedPane> and/or 
<t:panelTab> is it's own discussion.

Paul Spencer