Update grid.grouping.js

 1. support of "not exact" grouping by introducing `isInTheSameGroup` array of callbacks in `groupingView`.
 2. more flexibility in constructing of `displayField` by introducing of `formatDisplayField` array of callbacks in `groupingView`.
Fix typo in inline navigatoe
Merge pull request #452 from OlegKi/master

not exact grouping / grouping by intervals of values
onSelectRow will now be called on gridReload if there was a row selected
Merge remote-tracking branch 'upstream/master'