Updates to the board status script

This is the first major re-work for the board status script.
Summary:
- Added a command to the getrevision.sh script to retrieve tagged
  revision.

- Results are placed in a dynamically generated temporary location.
  This makes it easy to do multiple trial runs and avoids polluting
  the coreboot directory.

- Results are stored in a directory with the following form:
  <vendor>/<mainboard>/<tagged_revision>/<timestamp>/
  Vendor and mainboard are obtained from CONFIG_MAINBOARD_DIR so that
  hierarchy is consistent between coreboot and board-status.

- The results directory is used as the commit message.

- board-status repository is checked out automatically if results are
  to be uploaded.

TODO:
- Add ability to run commands which may fail. Currently we assume
  any failure should terminate the script, but some commands can be
  made optional.

Successfully uploaded first result to board-status repository. See
http://review.coreboot.org/gitweb?p=board-status.git;a=summary .

Change-Id: Icba41ccad4e6e6ee829b8092a2459c2d72a3365b
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/4039
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/.gitignore b/.gitignore
index 1cdabfc..c172244 100644
--- a/.gitignore
+++ b/.gitignore
@@ -55,6 +55,7 @@
 
 util/*/.dependencies
 util/*/.test
+util/board_status/board-status
 util/cbfstool/cbfstool
 util/cbmem/.dependencies
 util/cbmem/cbmem