use ToUpperInvariant instead, this is what dotnet recommends

bump

memory usage improvements

- add console app for testinng allocations
- reduce allocations in various places
- some refactoring and cleanup
- bump version

Merge pull request #10 from vforteli/fix/optimizations

Fix/optimizations

Merge pull request #9 from vforteli/fix/readme

add readme to package

Merge pull request #8 from vforteli/fix/performancetweaks

testing substitutions first allows in many cases to try less candidates

Merge pull request #7 from vforteli/feature/streaming

Feature/streaming

Update build.yml

Update README.md

Merge pull request #5 from vforteli/feature/ienumerablesupport

Feature/ienumerablesupport