If you call scons with the fist argument set to menuconfig, that means
to run menuconfig on the path following it. Or in other words, if
you ran this command:
scons menuconfig build/foo/bar
That would tell SCons to set up a build directory at the path
build/foo/bar, and then invoke menuconfig so you can set up its
configuration.
In addition to using this mechanism to set up a new build directory, you
can also use it to reconfigure an existing directory.
This supplements and does not replace the existing mechanism of using
"build/${VARIANT}" to select a config with defconfig.
Change-Id: Ief8e8c2ee6477799455c2004bef06c64be5cc1db
1e84d9f941