fix: missing API in RowEditor and examples/example3a-compound-editors: compound editor API corrected to match the current SlickGrid editor API requirements.
slick.editors.js defined SelectCellEditor twice; merged both; example3c now correctly uses jquery-multiselect but the select list is still faulty.
provisionally fix API for the CompositeEditor; see TODO in plugins/slick.composite.editor.js for more work that needs to be done. Now at least the slickgrid intern API checking assert()ions don't fire any more.
example6: remoteDataSource: crashes gone; flow still broken.
fixed a few crashes in the examples; the event itself is not passed as the `.e` member of the event extra data object as the event is always available as a separate parameter anyway. (Older revisions did this. It has been cleaned up a while ago, though.)
fixed several bugs when headers are or have been re-ordered by dragging them (testcase: examples/example-simple-with-order-columns.html):

- fix: assert()s fired on mouseenter/mouseleave events during a column drag: this hinted at these events being fired under undesirable circumstances. Now a header drag (re-order action) does NOT fire SlickGrid onMouseEnter/onMouseLeave events any more; this would only confuse userland code without any benefits -- as the header drag events are also 'exported' as SlickGrid events, so userland code can observe closely what's going on and mouseenter/mouseleave is highly erratic and depends largely on how the user moves the mouse while dragging)

- fix crash/assumption failures in onColumnResizeDblClick(): you CANNOT call getCellFromNode() on a HEADER element as those do not have the .lNNN classes (NNN being a column number).

- fix: the previous item's misuse of getCellFromNode() uncovered a faulty (inaccurate) regex-based column decode: as the header classes include a class named `level0` the original regex `/l\d+/` would incorrectly match on the last part of that class (another reason why use className is frowned upon; modern browsers have classList, though granted this way is faster when you need to grab a numeric piece from one of the element classes).

- also fixed the check for another regex: RE.execNextFlashPhase() fails with NULL return OR returns a match array; given `/_(\d+)_/` the .exec() cannot succeed and produce an empty subexpression match (`\d+`) at the same time hence a simple check suffices. Besides, the original check would have fatally crashd on an non-match anyway (while trying to access an index on a NULL var instead of an array object).