add git ignore
Using /proc/mounts in unix system

It seems that `/proc/mounts` is a better way than `mount` to list all mounted filesystems in unix.
With this system is also possible to show an OpenVZ root disk mounted with simfs.

Some literature on the topic: http://unix.stackexchange.com/a/12086/33366 and http://unix.stackexchange.com/a/24230/33366
renamed variables name for better readability
add red warning if space on disk is under 10%
Merge pull request #11 from endelwar/better-filesystem-free-space

Better filesystem free space