camelCaseEverything includingFunctionsAndMethods() and also fieldsInOptionsObjects

[ronyeh]

I was going through old issues to categorize them for 4.0 | 4.x | 5.0.

https://github.com/0xfe/vexflow/issues/348 https://github.com/0xfe/vexflow/issues/1070

I think for the future 5.0 release, we should make a pass through the entire code base and banish_the_underscores so that we can useCamelCaseForEverything.

We can add a big warning to the CHANGELOG for version 5.0, including a list of changed public members (the_old_way => theNewWay), so developers can easily search and replace in their projects.

Hopefully, now that we are in TypeScript, compiler errors will help catch any issues with migrating from 4.x to 5.0.