* Contents:
  - Summary
  - Usage
  - Implementation summary
  - Output
  - TODO

* Summary:
  This is used for printing what is about to happen between the current and last
  builds, for example:

  $ bitbake core-image-sato
  # Edit some recipes
  $ bitbake-whatchanged core-image-sato

  The changes will be printed.

* Usage:
  bitbake-whatchanged [[opts] recipe]

* Implementation summary:
  - Use the "STAMPS_DIR=<path> bitbake -S recipe" to generate the new
    stamps, compare these stamps to the one in the old stamps dir (tmp/stamps),
    so we will get what are changed.

  - When the "-v" (verbose) is not specified:
    > Figure out the newly added tasks
    > Figure out the PV (including PE) and PR changed tasks
    > The left tasks are the ones that the "Dependencies" changed tasks

  - When "-v" is specified:
    > Figure out the newly added tasks
    > Use bb.siggen.compare_sigfiles to figure out the details

* Output, for example (core-image-sat...