don't return Result for infallible functions

Dependencies

• [2] I52XSRUH Massive cleanup, and simplification
• [3] KVBLRDOU Concatenating edits with order conflict resolutions (if relevant), and parsing the text format of the result
• [4] 7A2TSC4P Conflict solving code (FOLDER edges)
• [5] WZVCLZKY address clippy lints
• [6] ZXTHL45O address clippy lints
• [7] UBCBQ5FG Removing pijul/src/commands/checkout.rs (unused file), as well as litorg comments
• [8] 74HX2XZD Cleanup and debugging
• [9] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• replacement in libpijul/src/pristine/mod.rs at line 325
  [2.39007]→[2.39007:39237](∅→∅)
  − Ok(Position {

  − change: if let Some(p) = pos.change {

  − if let Some(p) = txn.get_internal(p) {

  − p

  − } else {

  − return Err(crate::Error::InconsistentChange);

  − }
  [2.39007]

  [2.39237]
  + let change = if let Some(p) = pos.change {

  + if let Some(p) = txn.get_internal(p) {

  + p
• replacement in libpijul/src/pristine/mod.rs at line 329
  [2.39254]→[2.39254:39287](∅→∅)
  − change_id

  − },
  [2.39254]

  [2.39287]
  + return Err(crate::Error::InconsistentChange);

  + }

  + } else {

  + change_id

  + };

  +

  + Ok(Position {

  + change,
• replacement in libpijul/src/diff/replace.rs at line 37
  [3.781057]→[3.781057:781094](∅→∅)
  − ) -> Result<(), anyhow::Error> {
  [3.781057]

  [3.781094]
  + ) {
• replacement in libpijul/src/diff/replace.rs at line 80
  [3.782557]→[3.782557:782596](∅→∅)
  − return Ok(());
  [3.782557]

  [3.782596]
  + return;
• edit in libpijul/src/diff/replace.rs at line 96
  [3.783039]→[3.783039:783054](∅→∅)
  − Ok(())
• replacement in libpijul/src/diff/mod.rs at line 111
  [3.797108]→[3.797108:797127](∅→∅)
  − )?
  [3.797108]

  [3.797127]
  + );
• replacement in libpijul/src/diff/mod.rs at line 114
  [3.797176]→[3.797176:797262](∅→∅)
  − self.replace(&d, &mut conflict_contexts, &lines_a, &lines_b, &dd, r)?
  [3.797176]

  [3.797262]
  + self.replace(&d, &mut conflict_contexts, &lines_a, &lines_b, &dd, r);
• replacement in libpijul/src/diff/delete.rs at line 21
  [3.805988]→[3.805988:806025](∅→∅)
  − ) -> Result<(), anyhow::Error> {
  [3.805988]

  [3.806025]
  + ) {
• edit in libpijul/src/diff/delete.rs at line 37
  [3.806419]→[3.806419:806434](∅→∅)
  − Ok(())