Clean up content-scope wrapping in getEventListeners
Fix recognition of getEventListener return values
Issue 6975: Style panel right-click doesn't work when SVG <image> tag is selected

https://code.google.com/p/fbug/issues/detail?id=6975
Remove some remnants of E4X
Remove unnecessary checks

XMLDocument inherits from Document
Avoid touching .callee for 'arguments' tests

It throws in strict mode, and checking [[Class]] is more correct anyway.
Use Array.isArray instead of Arr.isArray
Simplify Arr.unique a bit
Remove unnecessary try-catch
Issue 6979: Toggles missing when 'Show Enumerable Properties Only' is off
Merge branch 'master' of github.com:firebug/firebug
Revert "Issue 6979: Toggles missing when 'Show Enumerable Properties Only' is off"

This reverts commit 8698e7cc1574b528a2040d3739235545a21b981b.
Issue 6979: Toggles missing when 'Show Enumerable Properties Only' is off (proper fix)
Issue 6982: Built-in array methods should be treated as DOM properties

https://code.google.com/p/fbug/issues/detail?id=6982
Issue 6983: Remove all cookies shortcut doesn’t have a tooltip
Changed "control" modifier to "accel" modifier to ensure that the
shortcuts also work on Mac OS
Merge with the master