Merge pull request #30 from terrible-broom/master

don't start container if failed to mount some configured mountpoints
Merge pull request #31 from terrible-broom/master

Umount all mountpoints before stopping container.
* Fixed unmounting all mountpoints before stopping container
* Addding stripping trailing slash in mountpoint --to option
Merge pull request #32 from spuzirev/master

Fixed unmounting all mountpoints on stopping container (2c483df9f66d59c7a5b9880ead8e7eeebc0c7816 fix).
Fixed umounting mountpoints at container stop.