only in a couple of places and all of them except for one were easily
converted to use Lst_First/Lst_Succ. The one place is compatibility
mode in job.c where the it was used to advance to the next command on
each invocation of JobStart. For this case add a pointer to the node to
hold the currently executed command.
rid of a lot of uneccesary casts and temporary variables that have just
obfuscated the code. This also let's us implement a couple of the one-
liner list functions as macros (the first one is Lst_IsEmpty) and
simplify life once we start to throw consts on the code.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.