Rename ambiguous methods to be more verbose

[pinepain]

Some methods, e.g. SymbolValue::for() could be improved, e.g. SymbolValue::createFor() looks more clear and self-descriptive. There are plenty of a kind. This task is vague by it's nature and in general it requires you to walk through stubs and see what looks strange or what may be hard to understand for end-users and what is not intuitive. BC-breaks are fine at this step.