Expressions Provider

- Updated to MiniPlaceholders v3 - Renamed project as ExpressionsProvider - Unlike other expansions, this expansion has now become a separate project (plugin/mod), which provides placeholders to MiniPlaceholders. - The way user expressions are loaded has been refactored. They are now created from the expressions.properties file, and no longer require the use of multiple \ characters to nest placeholders. You simply need to have a hierarchy of square brackets. For example, if you start with a quotation mark “ and want to place a placeholder argument inside it, you must use the other type of quotation mark ', and if another argument is required inside that argument, it must be interspersed with the other type of quotation mark ”. The wiki explains this better and provides examples.