ScmProj plugin 0.6 "The White Mountain"

New features:

 * Project v2: new layout of the control branch: toplevel branch of each
   project and subproject should have .bzrmeta/scmproj/project.cfg file with
   project config. No more separate .scmproj control branch needed.

 * Project v2 is now default one. Old projects are still supported in all
   operations except ``project-init``, so you can't create old project anymore
   with ``project-init`` command.

 * Config files for projects v2 have the same format as before, but alts and
   subsets are not supported in v2.

 * ``project-command`` for project v2 now executes actions for control branch
   as well as component branches.

 * Support for snapshots:

   * ``project-commit`` creates snapshots for main project and all
     subprojects.
   * ``project-get`` uses snapshots for main project and subprojects as well.
   * added option ``--revision`` for command ``project-get`` to allow clone
     of specified revision of main project root branch (with snapshots) and
     get other components and subprojects based on the snapshot of main root
     branch.
   * ``project-update`` command uses snapshot information to update root
     branches of subprojects, as well as plain components.
   * added option ``--revision`` for command ``project-update`` to allow
     update the toplevel branch of the project to specified revision
     and then update all components and subprojects based on the snapshot
     of that revision. **Limitation**: for update ``bzr pull`` command used
     under the hood, so it's not possible to update branches to older
     revisions (either for toplevel branch, component branches,
     or root subproject branches).

Improvements:

 * Improved support for executing project commands (update, commit, push) in
   subprojects recursively.

Deprecated features:

 * Hidden command ``chdir`` deprecated now, and will be removed in the next
   release.
 * project-get: several options marked as deprecated:
    * --control-branch-only
    * --components-only
    * --alt
    * --subset
    * --full-set
 * project-update: option --components-only marked as deprecated.
 * project-publish: several options marked as deprecated:
    * --alt
    * --components-only
    * --subset
    * --full-set
 * project-command: several options marked as deprecated:
    * --alt
    * --subset
    * --full-set
 * project-commit: several options marked as deprecated:
    * --components-only
    * --subset
    * --full-set