Version 0.2.0

BEWARE On-disk format is changed. You won't be able to use backups created with 0.1.0.

• Added command snap info
• Added command snap filelist
• Labeling for snaps (command snap label and -l flag to snap take)
• Added a prefix path to select files to restore (prefix-path when doing snap restore).
• Better commands layout
• Shallower dir structure
• Randomized IV for SipHash
• Use simple siphash as hash, without any suffix
• Fix: empty dirs weren't restored