Trying to fix channel touch

Dependencies

• [2] 3AMEP2Y5 More convenient interface for channels
• [3] G6S6PWZE Do not touch the channel if this is a partial record
• [4] DJYHARZ7 Skipping old files when recording
• [*] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).
• [*] GHO6DWPI Refactoring iterators

Change contents

• edit in pijul/src/commands/record.rs at line 155
  [3.298]

  [3.53]
  + debug!("oldest = {:?}", oldest);
• replacement in libpijul/src/record.rs at line 664
  [3.601]→[2.1975:2021](∅→∅)
  − > txn.last_modified(channel))
  [3.601]

  [3.2499]
  + >= txn.last_modified(channel))
• edit in libpijul/src/pristine/sanakirja.rs at line 1350
  [7.47821]

  [7.47821]
  + debug!("touch_channel: {:?}", t);