Bug 887515 - Replace multiple tab closing prompt with a menuitem to restore multiple tabs. r=ttaubert

--HG--
extra : rebase_source : 743b8bb459802675e38ef2ab8e8cee2c41b90f90
Bug 893004 part 1.  Remove Navigator classinfo.  r=smaug
Bug 893004 part 2.  Remove various no-longer-used XPCOM bits from Navigator, except the ones from nsIDOMNavigator.  r=smaug

--HG--
rename : dom/network/interfaces/nsIDOMNavigatorNetwork.idl => dom/network/interfaces/nsIMozNavigatorNetwork.idl
Bug 893004 part 3.  Remove the unused-from-C++ bits of nsIDOMNavigator, except the ones that share implementation with WebIDL anyway.  r=smaug

Note that I believe we could remove all these remaining attributes too; it's just some tedious work.
Bug 892510.  Cache whether we're only-whitespace on textnodes so we don't have to keep figuring that out over and over again.  r=smaug
Bug 894874.  Fix .selectedStyleSheetSet to consider all the sheets even after it finds an enabled sheet.  r=smaug