MultiSelect With extended select doesn't work as expected

[HarshadNarayane]

Steps to reproduce

1. Make sure you have 10 records in grid.
2. Select record 2nd to 5th using SHIFT key.
3. Count if pagination bar is used will be displayed accurately as 4 (selected records are 2,3,4 and 5).
4. Now select 1st record , you'll be able to see that records 1 and 2 are selected which is expected behavior but the count on pagination will be 5 (It will maintain history as 3,4 and 5 are also selected).
5. This seems to be a major flaw and needs to e resolved asap.
6. The same can be reproducible on http://oria.github.io/gridx/demos/indirectSelect.html under IndirectSelect with extended selection (trigger on cell) section.