Add abillity for multi and range-selection to events.js

Add the abillity to select multiple rows, with a multi-selection using the
CTRL-key or a range-selection using the shift-key. Also fix several issues in
the Multi-Controller of the Backend.

refs #5765
Move functions to perform single, multi and range-selection into the ui module

refs #5765
Fix issues issues with javascript multiselection

refs #5765
Fix layout of MultiController views

refs #5765
Add PieChart to display hosts and services, improve layout and fix flag
checkboxes

refs #5765
Fix configuration checkboxes and colors in piecharts

refs #5765
Preserve multiselection during refresh

refs #5765
Fix query that finds the nearest container of a table row and stores it.
Merge branch 'bugfix/fix-multiselection-5765'