Add support for setting rlimit for contianer

Adds a new item to the config struct []*Rlimit
Rlimit takes a type (ie, syscall.RLIMIT_NOFILE) and the hard/soft limit
(As max/cur)

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Merge pull request #280 from cpuguy83/add_rlimit_support

Add support for setting rlimit for contianer
Add container spec

This document specifies the current container specification with all the
underlying setup and configuration that goes into making a container.
This is the v1 spec that is today but allows for flexability when we
introduce more features such as seccomp default profiles and more.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Merge pull request #282 from crosbymichael/spec

Add container spec
Change namespaces config to include path for setns

This changes the namespace configuration on the config to include the
name of the namespace along with an optional path.  This path is used to
point to a file of another namespace for the namespace so that it can be
joined in place of the empty, initialized namespace.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>