Remove forgotten wip-tags from features
headlessCamelCase style for methods/functions
Implement rules for member variables
Allow postfix to end of headlessCamelCase

Not really ideal solution, because likely there are styles that consider
headlessCamelCase names like this an error. But this allows to have
variable name postfixes like "memberVariableM" that the first target
style includes.

A better and more general solution can be devised later, if necessary.