Add Edit [element] style to context menu

Some elements have style in addition to their normal element properties (eg. staff, measure, etc.). And right click should pull up a link to edit both the individual element properties as well as the corresponding element's style page.

This is purely a UI grievance from the point of view from new users to help them find the right dialog to do what they want (e.g. change the frequency of measure numbers, spacing between staves, etc.).

Definitely nothing that needs anyone's attention asap. Something to consider for 0.9.6