clean up build a bit

First we fix configure.in:
 - search for a prefixed ar program rather than just "ar"
 - setup install and mkdir helpers for the Makefile
(ignore the generated configure here as it's just `autoconf`)

Then we update the Makefile.in:
 - get paths from configure
 - setup install/mkdir helpers
 - add an install target that utilizes DESTDIR and all that fun stuff

This allows us to slim down the libresample ebuild (a follow up commit)
to almost nothing since the build system now respects all the right
pieces.

For good measure, we also throw in gitignore.

BUG=chromium-os:22406
TEST=`emerge-amd64-generic libresample` now installs into /usr/lib64
TEST=`emerge-x86-generic libresample` still uses /usr/lib

Change-Id: I64b274b2684c9bbe2ac2cb84eec383572d565529
Reviewed-on: https://gerrit.chromium.org/gerrit/11044
Reviewed-by: Sonny Rao <sonnyrao@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
4 files changed