portage: add wrappers/helpers for interacting with portage
This creates emerge/ebuild/portageq wrappers people can execute directly
(as well as the android build system will use), and the target-specific
config files they rely on.
The tools should work off of the android env vars to locate the current
board/build directories rather than hardcoding any of them in the output.
TEST=built packages and they worked in qemu
5 files changed