Store last-used configure arguments in a config.status file.
Don't generate conf.log, put that information in --verbose.
make it possible to use relative paths as input?

QConf can be considered complete.  There are some todo items in this file,
but they are not vital.  I've added some rationale text for each one to
explain why.

- cross-compile?  (set host / target arches)

  I haven't needed to cross-compile yet, so I haven't looked into this.
  Probably one can do it anyway by setting a bunch of environment variables,
  like CC, QMAKESPEC, etc.  Maybe when we start seeing active Qt4/Embedded
  usage, this can be revisited, but even still it may not need to be
  explicitly supported.

- turn .qc file into qmake-style format instead of xml?

  XML is human-readable and nice for application data interchange, but it
  isn't very nice to have to write by yourself.  I'm using it only because
  I didn't want to write a parser.  I generally hate it when applications
  require manual XML editing (I'm looking at you jabberd), and here I am
  committing the same offense.

  Fortunately, the XML files are usually only a handful of lines, and they
  work well enough ("if it ain't broke...").  Even so, I think it is worth
  looking into supporting an easy-to-write, flat-text format like what is
  used for qmake.
