* check build and source tool versions from bakeconf.xml
* compressed 'bake' binary
* add <patch> xml node in source node.
* export env vars that need to be modified in shell from build objects
* find a way for users to specify an env var for build
* find a way to deal with per-module options that are not build-tool-dependent
* change $INSTALLDIR to ${PREFIX} in xml
* make <installed value=""> tags work when mving the directory.
* check that module names do not contain reserved characters for paths.

* missing commands:
  - diff in ModuleSource
  - reset in ModuleSource
  - clean in ModuleSource
  - query modules, deps, etc.