package ipk bbclass: store build branch and revision in ipkg metadata

package ipk bbclass: store build branch and revision in ipkg metadata

The ipkg metadata will look like this now:

koen@dominion:/OE/angstrom-dev/deploy/glibc$ dpkg-deb -I ipk/am3517-evm/matrix-gui_1.3-r19.0.6_am3517-evm.ipk
 new debian package, version 2.0.
 size 24112 bytes: control archive= 540 bytes.
     629 bytes,    13 lines      control
 Package: matrix-gui
 Version: 1.3-r19.0.6
 Description: Matrix GUI for Qt X11
 Section: multimedia
 Priority: optional
 Maintainer: Angstrom Developers <angstrom-distro-devel@linuxtogo.org>
 License: BSD
 Architecture: am3517-evm
 OE: matrix-gui
 Homepage: https://gforge.ti.com/gf/project/matrix_gui/
 Build: org.openembedded.dev/f35ab2d
 Depends: matrix-gui-common, libpng12-0, libfreetype6, libz1, libgthread-2.0-0, libqtwebkit4, libphonon4, libqtdbus4, libqtxml4, libqtgui4, libqtnetwork4, libqtcore4, libglib-2.0-0, libc6, libstdc++6, libgcc1
 Source: svn://gforge.ti.com/svn/matrix_gui/;module=trunk;proto=https;user=anonymous;pswd=''
koen@dominion:/OE/angstrom-dev/deploy/glibc$

Signed-off-by: Koen Kooi <koen@openembedded.org>
Acked-by: Martin Jansa <Martin.Jansa@gmail.com>
Acked-by: Chase Maupin <chase.maupin@ti.com>