fix(3901): Raise rowsVisibleChanged on setVisibleRows.

[jeremy-j-ackso]

Several issues and Stackoverflow threads indicate that one would expect the rowsVisibleChanged event to be emitted when a filter is applied. It seems pretty rational that rowsVisibleChanged ought to be raised by setVisibleRows(), which is what this small PR implements.

A related issue not addressed by this PR is that many of the SO threads and issues also seem to believe that a filtersChanged event should be raised after the visible rows are changed via filters. This is a common misunderstanding of how ui-grid operates in that changing filters are a different operation from changing visible rows. Since there seems to be a timing/ordering issue between when filtersChanged is raised and setVisibleRows is called this probably merits discussion before/if a change is made. Perhaps a tutorial page on events could alleviate this confusion?

#3901
#4138
http://stackoverflow.com/questions/27301690/angular-ui-grid-ng-grid-filterchanged-firing-too-frequently
http://stackoverflow.com/questions/33764946/how-to-get-filtered-data-from-paged-ui-grid

[mportuga]

@jeremy-j-ackso It might make sense to add a unit test for this.

[dlgski]

Accepting this PR. Can you update tutorial as you suggest as well?