Added MCommandExtensionsV1 as an extensible way of adding new virtual functions to CCommandBase without breaking BC.
Using this, added a custom error code resolver and added lots of Software Install errors to swi.
These two executables exists to allow fshell to eclipse the ROM based "econs.dll". This can't be done
within the .SIS file because the app installer doesn't allow ROM files to be eclipsed.
fshell_inst.exe copies "<install_drive>:\sys\bin\iocons.dll" to "<install_drive>:\sys\bin\econs.dll".
It is launched by the tool-kit .SIS file at install time.
fshell_uinst.exe deletes "<install_drive>:\sys\bin\econs.dll".
It is launched by the tool-kit .SIS file at uninstall time.