address non-controversial clippy lints

Dependencies

• [2] I52XSRUH Massive cleanup, and simplification
• [3] Q45QHPO4 Feedback on network stuff
• [4] UNZXTNSJ Change text format: order dependencies in the order they were on the channel at record time
• [5] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• replacement in pijul-macros/src/lib.rs at line 17
  [3.765]→[3.765:814](∅→∅)
  − s.to_uppercase().nth(0).unwrap()
  [3.765]

  [3.814]
  + s.to_uppercase().next().unwrap()
• replacement in libpijul/src/tests/unrecord.rs at line 345
  [3.259350]→[3.259350:259437](∅→∅)
  − // Should fail: we're resurecting a file in a directory that doesn't

  − // exist anymore.
  [3.259350]

  [3.259437]
  + // Should fail: we're resurrecting a file in a directory that doesn't

  + // exist any more.
• replacement in libpijul/src/tests/unrecord.rs at line 770
  [3.271732]→[3.271732:271772](∅→∅)
  − write!(w, "blabla\nblibli\n")?;
  [3.271732]

  [3.271772]
  + writeln!(w, "blabla\nblibli")?;
• replacement in libpijul/src/tests/unrecord.rs at line 780
  [3.272003]→[3.272003:272035](∅→∅)
  − write!(w, "blabla\n")?;
  [3.272003]

  [3.272035]
  + writeln!(w, "blabla")?;
• replacement in libpijul/src/tests/unrecord.rs at line 846
  [3.273971]→[3.273971:274003](∅→∅)
  − write!(w, "blabla\n")?;
  [3.273971]

  [3.274003]
  + writeln!(w, "blabla")?;
• replacement in libpijul/src/pristine/sanakirja.rs at line 1186
  [3.572491]→[3.572491:572565](∅→∅)
  − changes: changes,

  − revchanges: revchanges,
  [3.572491]

  [3.572565]
  + changes,

  + revchanges,
• replacement in libpijul/src/pristine/mod.rs at line 570
  [2.45655]→[2.45655:45700](∅→∅)
  − while let Some((k, v)) = cursor.next() {
  [2.45655]

  [2.45700]
  + for (k, v) in cursor {
• replacement in libpijul/src/pristine/mod.rs at line 618
  [2.47042]→[2.47042:47087](∅→∅)
  − while let Some((k, v)) = cursor.next() {
  [2.47042]

  [2.47087]
  + for (k, v) in cursor {
• replacement in libpijul/src/pristine/mod.rs at line 1211
  [2.52658]→[2.52658:52682](∅→∅)
  − flag: flag,
  [2.52658]

  [2.52682]
  + flag,
• replacement in libpijul/src/pristine/mod.rs at line 1255
  [2.53797]→[2.53797:53821](∅→∅)
  − flag: flag,
  [2.53797]

  [2.53821]
  + flag,
• replacement in libpijul/src/fs.rs at line 160
  [3.742829]→[3.742829:742865](∅→∅)
  − parent_inode: parent_inode,
  [3.742829]

  [3.742865]
  + parent_inode,
• replacement in libpijul/src/change.rs at line 1651
  [3.887744]→[3.887744:887782](∅→∅)
  − write!(w, "\n")?;
  [3.887744]

  [3.887782]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1669
  [3.888474]→[3.888474:888512](∅→∅)
  − write!(w, "\n")?;
  [3.888474]

  [3.888512]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1681
  [3.888888]→[3.888888:888922](∅→∅)
  − write!(w, "\n")?;
  [3.888888]

  [3.888922]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1685
  [3.889088]→[3.889088:889126](∅→∅)
  − write!(w, "\n")?;
  [3.889088]

  [3.889126]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1688
  [3.889239]→[3.889239:889277](∅→∅)
  − write!(w, "\n")?;
  [3.889239]

  [3.889277]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1698
  [3.889551]→[3.889551:889585](∅→∅)
  − write!(w, "\n")?;
  [3.889551]

  [3.889585]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1704
  [3.889866]→[3.889866:889904](∅→∅)
  − write!(w, "\n")?;
  [3.889866]

  [3.889904]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1775
  [3.892938]→[3.892938:892972](∅→∅)
  − write!(w, "\n")?;
  [3.892938]

  [3.892972]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 1783
  [3.893324]→[3.893324:893358](∅→∅)
  − write!(w, "\n")?;
  [3.893324]

  [3.893358]
  + writeln!(w)?;
• replacement in libpijul/src/change.rs at line 2669
  [3.927244]→[3.927244:927270](∅→∅)
  − write!(w, "\n")?;
  [3.927244]

  [3.927270]
  + writeln!(w)?;
• replacement in libpijul/src/alive/dfs.rs at line 370
  [3.1012785]→[3.1012785:1012842](∅→∅)
  − main_side.sccs.extend(side.sccs.iter().map(|&x| x));
  [3.1012785]

  [3.1012842]
  + main_side.sccs.extend(side.sccs.iter().copied());