Initial memory tracker HAL

Squashed commit of the following, from AOSP display:
libmemtrack: Add libmemtrack to HAL directory listing

Change-Id: Ifbe55a339d589ad1bfab07fef684a738976877bd

commit 454565c66a5d068c0722aa3bb1fccc4c383a5808
Author: Colin Cross <ccross@android.com>
Date:   Mon Sep 30 13:09:02 2013 -0700

    fix fd leak in memtrack.msm8960

    Close smaps_fd when exiting function.

    Bug: 11007903
    Change-Id: I4a9fcd1e84aae195d229e5dd11f99ccb9f6f5006

commit 28c93c950cd82667a43dd0dd64043274eb7a1e55
Author: Colin Cross <ccross@android.com>
Date:   Mon Sep 16 15:16:08 2013 -0700

    Fix remainig exynos references

    Also fix a compile warning by replacing enum with int in the getMemory
    function.

    Change-Id: Ic4bbba425486bb7f456e928968afa5f2b04ca7ea

commit b46313b2e4d0e7fd1a475bf26ce396bcd0243921
Author: Colin Cross <ccross@android.com>
Date:   Fri Sep 6 18:03:02 2013 -0700

    Initial msm8x64 memory tracker HAL

    Reads memory info from kgsl to track unaccounted for GL and ION
    memory.  Right now it has to parse every allocation and then
    cross-reference it against /proc/pid/smaps.  It would be faster
    to modify the kgsl driver to keep counters that could just be
    read directly.

    Bug: 10294768
    Change-Id: Icb17558f03ce53bc594fbee097e51fe82e15dc31

Change-Id: I7816cf5f506ac94229646013683bdba674110ede