Canonicalise paths (reset and credit) before stripping off the prefix

Dependencies

• [2] NLGQAH4H Credit and reset relative to current directory instead of the root
• [*] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• edit in pijul/src/commands/reset.rs at line 52
  [2.97]

  [2.97]
  + let root = std::fs::canonicalize(&root)?;
• edit in pijul/src/commands/credit.rs at line 46
  [2.260]

  [2.260]
  + let root = std::fs::canonicalize(&root)?;