buildhistory: Change default BUILDHISTORY_DIR to TOPDIR

:Release Notes:
* Like PERSISTENT_DIR, I expect BUILDHISTORY_DIR to be more persistent
  than the TMPDIR directory is.
* WARNING: People with existing checkouts in TMPDIR/buildhistory
  need to move it to new location first (in order to save history)

:Detailed Notes:
Backport of oe-core commit d3ad9a4c573fec08b5606a4c3e86f93cb95e8718

:Testing Performed:
Build tested, buildhistory output checked.

:QA Notes:
No change in image.

:Issues Addressed:
[GF-3127] Backport newer buildhistory.bbclass
[GF-9902] Disable checking for package version decreases

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@lge.com>

Change-Id: I1ca40045921c649aafbdc616ee552e10f293b9e7
Reviewed-on: https://g2g.palm.com/3045
Reviewed-by: Herb Kuta <herb.kuta@lge.com>
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Tested-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>