Improve AppArmor policy load

jdstrand> this needs more fleshing out: eg, systemd integration, split up kernel postinst work item into smaller chunks, parser into a library (systemd)

Work items for ubuntu-14.05:
[seth-arnold] Discuss apparmor profile load strategy: DONE
[mdeslaur] investigate/benchmark/bootchart converting apparmor to an upstart job (before lightdm/other login managers, console, sysv scripts): DONE

Work items for ubuntu-14.06:
[mdeslaur] convert apparmor to use upstart job: DONE

Work items for ubuntu-14.07:
[jjohansen] prototype parser to generate multiple versioned apparmor cache files: DONE
[tyhicks] upstream jj's parser patches for multiple versioned apparmor cache files: POSTPONED
[tyhicks] determine proper directory structure for versioned apparmor cache files: POSTPONED
[tyhicks] implement kernel postinst policy compiles: POSTPONED
[tyhicks] implement hook to clean up cache files on kernel uninstall: POSTPONED

Work items for later:
[tyhicks] create minimal library for cached profile loading in systemd/upstart: POSTPONED
[tyhicks] write systemd patch to load cached profiles at startup: POSTPONED
[tyhicks] submit systemd apparmor cache load patch upstream: POSTPONED
[mdeslaur] write upstart patch to load cached profiles at startup: POSTPONED
[tyhicks] write second-stage systemd unit for apparmor: POSTPONED
[tyhicks] review systemd profile switch functionnality: POSTPONED
[tyhicks] modify (if necessary) systemd profile switch functionnality: POSTPONED
[tyhicks] submit systemd profile switch patch upstream: POSTPONED
[mdeslaur] decide how to fix upgrade failures on apparmor policy load: POSTPONED
[mdeslaur] revert upstart distro patch to fail open on policy load: POSTPONED
[jjohansen] drive apparmor policy versioning to completion: POSTPONED
[tyhicks] update apparmor_parser to add v3 open rules to v2 policy: POSTPONED