cards can have multiple logical channels; each logical channel
has its own state of what is the current selected file + application.
Let's split the RuntimeState class into the global RuntimeState and the
per-lchan-specific RuntimeLchan class.
This code doesn't actually introduce any code that uses lchans other
than the basic logical channel (0), but just modifies the data model
to accomodate those in the future.
Change-Id: I7aa994b625467d4e46a2edd8123240b930305360
a6c0f880da