Refactor cgroups file locations
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Move systemd code into pkg
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Move raw cgroups into fs package (filesystem)
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Break down groups into subsystems
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Add remove method to subsystems
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Squashed commit of the following:

commit 75af1649b063abbc5d662fd2f8bc4ff62c927687
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 01:32:42 2014 -0400

    more refactor

commit 43b36d0f15d634497127bcb17dacaa70ae92e903
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 01:11:49 2014 -0400

    refactored cgroup param parsing to util func

commit e3738b0168a075bd92ec828879b0e46bdbbe3845
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 00:57:19 2014 -0400

    dat error checking

commit 57872bcc59403ecd308cfe97c78f73d6ca58d165
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 00:43:25 2014 -0400

    proper use of fmt.Errorf

commit 43dad6acc0cb21aac2b04ce074699879898ee820
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 00:36:45 2014 -0400

    proper placement of defer

commit b7f20b934b2bc92cd39397dbc608b77bff28493c
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 00:34:39 2014 -0400

    defers, error checking, panic avoidance

commit 7a9a6ff267f8806dfe6676486f73fe89b72968fb
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 00:22:00 2014 -0400

    data param to use container info instead of host

commit 0e0cf7309be1644687160d6519db792b23cd26e9
Author: Evan Hazlett <ejhazlett@gmail.com>
Date:   Sun Apr 20 00:11:29 2014 -0400

    added stats for cpuacct, memory, and blkio

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Refactor stats and add them to all subsystems
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Add external function to get cgroup stats
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Fix parsing of blkio files
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Reuse cpuacct stats for cpu subsystem
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Add freezer stats

This one is a problem because the most useful stat is a string and not a
float like verything else.  We may have to change the return type
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
work on cpu stats

Docker-DCO-1.1-Signed-off-by: Evan Hazlett <ejhazlett@gmail.com> (github: ehazlett)
Merge pull request #24 from ehazlett/cgroups-stats

more work on cpu stats
Refactor stat parsing to use only 8 fields
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Use cgo to get systems clock ticks for metrics
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #5328 from crosbymichael/refactor-cgroups

Refactor cgroups into subsystems and support metrics