2 - The overall scheme is altered.
first, all input files are processed until a combining phase is met.
then, all the combining phases are executed, the resulting files
are again processed until a combiner (or final) phase is met.
3 - The EM_DIR shell variable can be used to set ack's idea of the EM
home directory.
'hex' is the pid of the current invocation of ack in hex.
'unique' is a tail unique to this invocation.
2 - The outfile field is used to indicate default naming, can be ovrrriden
by the -o flag.
3 - Added handling for phases with multiple inputs (ego, linker).
would not need to be fed through a pre-processor.
This assumption proved false. Ack was altered and allows
use of a pre-processor on files produced by other passes.
