- Drop support for Subversion in the getrevision script and Makefile.
 - Add .gitignore and .gitattributes file (the latter to limit exports).
 - Restore modification dates of the exported files from the SCM.
 - Stop exporting SCM log dumps to CHANGELOG. This makes no sense.
 - Do not export the pre-"compiled" manpage. It can be generated like
   anything else from the code dump when we export the respective
   variable.
   The latter is added with this change.
 - Add some initial client-side git hooks
   * When committing check for obvious stuff you never want anyway:
     - white space errors
   * When pushing to the upstream repository check mandatory rules:
      - existing signoffs and acks in all new commits
      - no deletions or creation of branches
      - do not rewrite history of the precious branches, even if forced

NOTE: This patch is adapted from Stefan Tauner's original commit:
https://mail.coreboot.org/pipermail/flashrom/2016-November/014877.html



There are a few major differences:
- This uses coreboot's commit-msg hook which includes support for
  generating and appending Change-Id.
- djgpp-dos target removal is moved to a follow-up patch.
- Version string changes are moved to a follow-up patch.

Change-Id: I64eef21982cac0a0a7419bcd2c8a936672ae9cb2
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Signed-off-by: David Hendricks <dhendricks@fb.com>
Reviewed-on: https://review.coreboot.org/19206


Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>