Add --dry-run and --timing options

[samsrabin]

Also adds a few unrelated tests.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 99.30070% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 99.38%. Comparing base (ddde636) to head (dd3603d).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
relink.py	97.56%	1 Missing ⚠️
tests/test_relink.py	99.59%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #10      +/-   ##
==========================================
+ Coverage   96.99%   99.38%   +2.39%     
==========================================
  Files           3        3              
  Lines         432      652     +220     
==========================================
+ Hits          419      648     +229     
+ Misses         13        4       -9     

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