Implements ifup and ifdown.
Copied from https://github.com/WindRiver-OpenSourceLabs/meta-overc.git
as of commit aa89eebffe06e4aa04701eae9691cb3049cbaef9.
(From OE-Core rev: c1d1ccf994d9204f481e12ccb4e63a7c448bc9cd)
Signed-off-by: Joe Slater <jslater@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Joe Slater