FBTest fix for spy/2285 (since bug 843508)
FBTest: yet fix for 2285 (and keep compat with Fx21)
Fix bug where applying operand 'in' on some things throws an uncatchable error
Make backward compat function actually be backward compatible by returning the result
Fix for dom/attributes test, failing in Nightly. Related to issue 3790
Simplify test for NamedNodeMap (related to the previous commit and issue 6315)

http://code.google.com/p/fbug/issues/detail?id=6315
Issue 6317: 	Value attribute doesn't show up in console after it was added by JavaScript
Issue 6316: 	Improve usability of long (and wide) stack traces: file name on the left and other
Issue 6316: 	Improve usability of long (and wide) stack traces
FBTest: move firebug/2613 test into known-failures test list (bug 854139)
FBTest: create a new list for the test bot (without crashing tests, bug 854139)
Issue 6168: 	Update Firebug to use the new Private Browsing APIs
First check the new PB API (related to issue 6168)
It's better desing to put Cu.import()s at the top of the module (related to issue 6168)
Merge with master