* add new option 'env.exclude'
 * remove listed containers from graphs
some plugins need root privilege

 * lxc_cpu, lxc_cpu_time, lxc_proc, and lxc_ram need root privilege to execute lxc-ls
 * remove needless `lxc-ls`
 remove typos
add support for Ubuntu 12.04 and fix graph type

 * `lxc-cgroup -n $guest_name tasks` gives error on Ubuntu 12.04
 * location of 'tasks' sysfs file depends on which cgroup package is installed
 * graph type should be 'GAUGE'
Merge pull request #2 from mittyorz/precise

fix typos, add Ubuntu 12.04 support for lxc_proc