9 - Updated pull/merge logic on hook_buildmanager_build.

  Skip pull/merge command when subtree already matches make file. It's
  extraneous noise in the project's commit history.

	modified:   drushsubtree.drush.inc
Added drush log message when pull/merge is skipped.

	modified:   drushsubtree.drush.inc
Added --fast-but-noisy flag for buildmanager-build.

	modified:   drushsubtree.drush.inc