dsplit: Improve whitespace splitting
dsplit: Unwrap useless nesting
dsplit: Split by !
dsplit: Improve ! splitting
dsplit: Split by .
dsplit: Don't consume whitespace after closing a pair
Add .gitignore
Add existing tests (most results are outdated)
Test command fixes

- No echo
- Force entry point to avoid 16-bit executable error
- Fix "one"
Add test runner
Fix coverage test
runtests: Fix opts loading
.gitignore
runtests: Pass opts when dumping as well

(fixes obfuscation test dumps)
Add current test results
Use src.result for final, versioned result

This is to allow accidentally adding or comparing with in-progress
results of current or aborted reductions.
tests: Version progress (filtered reduction output)
Use unseeded RNG for --obfuscate --keep-length
runtests: Run dustmite via rdmd
dustmite: Improve --dump dependency formatting