Add validate method to search control

This validate method will tell the user which labels are invalid and instructs the user to remove them.

Signed-off-by: Don Naegely <naegelyd@gmail.com>
Warn the user if a call is pending in search control

While this is very unlikely, we cannot make any determination as far as the validity of values until the pending call is resolved so we check for pending calls now just in case the user moves with lightning speed and interrupts a pending call.

Signed-off-by: Don Naegely <naegelyd@gmail.com>
Merge pull request #515 from cbmi/issue-513

Add validate method to search control