Support remote files in Open Recent File menu

Open Recent File feature currently supports only local disk files.

As Netbeans has full fledged support for remote development,  support needs to be added for recently opened/closed remote file (rfs:// , sftp:// etc)

This feature would make it very convenient especially for opening last closed file in C++ remote development mode.

Required code changes

Recent files list is stored as system dependent file path. Replacing this with URLs obtained for URLMapper would be all that is needed