Closes #4589

Closes #4590

Closes #4569

Closes #4585

Issue #4497

Issue #4575

Closes #4576.

Issue #4559

Issue #4559

Issue #4572

Issue #4572

Closes #4499

Closes #4573

Closes #4568

Closes #4549

Issue #4537

Where it would return a nonsense offset when called for the end of
the document if the last line had line widgets above it.

Issue #4557

To forbid using the comment strings from their inner modes

Closes #4562

Closes #4563

Closes #4472

Issue #4560

Issue #4556

Closes #4554

Closes #4553

Closes #4552

  - Update keywords (remove `ifdef`. add `select`, `uninitialized` and `__END_LINE__`.)
  - Add new string literals (%q string and here docs).
  - Remove global variable syntax (because it is no longer supported.)
  - Improve indentation (fix #3887, and correct indentation of `abstract class`)

Closes #4548