overview map control destroys drag handler too late

[elemoine]

the overview map control destroys its drag handler after it destroys its OpenLayers.Map object (ovmap), this causes dereferencing null (map.events) when it the handler's destroy method deactivates the handler. Patch to come.

[elemoine]

patch-2383-r9898-A0.diff fixes it, tests pass in FF3.6b4.

[ahocevar]

These destroy issues are always more interesting to test in IE. So if you can confirm that tests also pass in IE, and that unloading the overviewmap.html example page does not cause an error in IE, you can commit.

[elemoine]

Tests pass in FF3.6b4, IE8, Chromium. The overviewmap.html example works as expected, an unloading the page does not cause error in any of the aforementioned browser.

[elemoine]

(In [9902]) overview map control destroys drag handler too late, r=ahocevar (closes #2383)