Scott Putterman's changes to make the folder pane work.

mailnews/base/public/nsIMsgFolder.idl

mailnews/base/public/nsIMsgHost.h

mailnews/base/src/makefile.win

mailnews/base/src/nsMsgFolder.h

mailnews/base/src/nsMsgLocalMailFolder.cpp

mailnews/base/src/nsMsgRFC822Parser.cpp

mailnews/local/src/nsMSGFolderDataSource.cpp

mailnews/mime/src/oldfile.cpp

mailnews/ui/messenger/public/nsIDOMMsgAppCore.h

mailnews/ui/messenger/resources/folder.xml

mailnews/ui/messenger/resources/frames.html

mailnews/ui/messenger/src/makefile.win

mailnews/ui/messenger/src/nsJSMsgAppCore.cpp

mailnews/ui/messenger/src/nsMsgAppCore.cpp