API Change: `ToCamelCase` preserves source string case

As ToCamelCase is a port of RoR's String#camelize, this change makes the return value of this method consistent with its origin. Thanks @dbainbri-ciena for raising this issue in #54.

This is a breaking API change. The return value of ToCamelCase("toCamelCase") was Tocamelcase and then it's ToCamelCase now. If this change breaks your code, please let me know and open new issue against this change. Thanks.

Use `strings.Builder` for better performance if it's available

See #46 for details. Thanks, @ninedraft.

`ToCamelCase` is aware of space and hyphen

Per @Ilyes512's request in #45, ToCamelCase is aware of space and hyphen now. The conversion rule is updated in #1. ToSnakeCase and ToKebabCase are updated to convert all unicode space, including tab, CR, LF, etc, to underscore or hyphen according to the new rule.

Add `ToKababCase` and fix some issues

I add a new method ToKababCase as mentioned in #41 per @Ilyes512's request.

I also fix some issues #36 #38 #39 in this release. Thanks all guys who raised these issues to me.

Upgrade `ToCamelCase` to support more reasonable cases

I upgrade ToCamelCase to support cases mentioned in #34 per @jhayotte's request.

All necessary functions so far

v1.0.0

fix #36. wrong skip checks in Squeeze