Update Portage to support fixing *.la and *.pc files.

*.la and *.pc files need to be fixed up in order to ensure packages link
against the right library when we try to build / install to different ROOTs.

BUG=chromium-os:11316
TEST=Compile with build_packages --nousepkg

Review URL: http://codereview.chromium.org/6370011

Change-Id: I99db793c3c0dc3fab7646a7fbb258fdc40b086a9
(cherry picked from commit 0448eb511f63b2a1a99e724fe72764473b4958a4)

Conflicts:

	pym/portage/const.py
	pym/portage/dbapi/vartree.py
3 files changed