AG-461 quick filter now uses '\n' instead of '_' so that when user filters with '_' it doesn't return all results

AG-372 stopEditingWhenGridLosesFocus now works with popup editors. previously you could not click inside a popup editor with stopEditingWhenGridLosesFocus=true

AG-384: scroll didn't reset when you were pinning right, and scrolling half way down, then unpinning.

AG-377: Put new property 'rowGroupColumn' onto the row node, as restrictToOneGroup didn't work with valueGetter otherwise. now the logic can depend on the new rowGroupColumn attribute rather than the field attribute on the row node (as the field attribute is missing when using valueGetter).