rename nwWorkingDir to nwworkingdir
Support 'nwfaketop' attribute of iframe

With 'nwfaketop' attribute window.parent and window.top
would return the iframe object rather than the parent frame
and the top frame.

See rogerwang/node-webkit#534
nwfaketop: Fix for more cases

The following should be emulated as a top level window:

"_top" navigation target
window.frameElement
location.ancestorOrigins

see the comments in rogerwang/node-webkit#534
nwfaketop: window.open need to find the fake top object
Merge pull request #3 from rogerwang/node

Pull from upstream