lshal: Refactor lshal to use an Lshal class; combined instance column with interface column

We need to be able to select columns, sort columns,
and do IPC calls fault-tolerently.
Refactoring lshal.cpp into an Lshal class for more
objective-oriented programming, so that global variables
can be avoided and less parameters will need
to be passed around.

Test: lshal outputs identical output as without this CL, except
with the column merged.

Change-Id: I9668c998da692222aef96ae67bbab8066172543d