* Test returns and exit codes on most command invocations
* Add start and end banners to make output easier to find in
long log files
* Adds die_if_error(), die_if_not_set() and is_set() to functions
* Add some function tests
Fixes bug 944593
Change-Id: I55e2962c5fec9aad237b674732b1e922ad37a62e
489bd2a62b