Add loading messages to multi column sorting

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>
bug #4626 Ctrl + click on a column not in sort triggers a server call to erroneous url

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>
Show loading message while updating sort

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>
Merge branch 'QA_4_3'

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>