* Transfer SmartLengthInputFilter in-header license
Transfer license for file "SmartLengthInputFilter.java" from me (Diego Rossi) to Tusky and therefore also change it from the original Apache 2.0 to currently GPLv3. This was a mistake that has been sitting around for way too long.
* Rewrite SmartLengthInputFilter from Java to Kotlin
This has been done by hand, without the custom copy-paste tool.
* Fix bad references in Java files using SmartLengthInputFilter features
* Shorten code in Java classes referencing SmartLengthInputFilter instance
* Refactor SmartLengthInputFilter from class to singleton Kotlin object
* Move hasBadRatio to become a toplevel function
* Patch up all the files affected by SmartLengthInputFilter changes
* Length in SmartLengthInputFilter is const 500, simplify code accordingly
* More meaningful name for toplevel function for checking trimming ability
* Add missing license header
Konrad Pozniak