the new file_lines_load() and file_lines_free() routines. Very useful!

the new file_lines_load() and file_lines_free() routines. Very useful!

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The following series of commits are for the new tdb based printing
backend. This completely replaces our old printing backend.

Major changes include:

- all print ops are now done in printing/*.c rather than scattered all
  over the place
- system job ids are decoupled from SMB job ids
- the lpq parsers don't need to be nearly so smart, they only need to
  parse the filename, the status and system job id
- we can store lots more info about a job, including the full job name
- the queue cache control is much better

I also added a new utility routine file_lines_load() that loads a text
file and parses it into lines. This is used in out lpq parsing and I
also want to use it to replace all of our fgets() based code in other
places.