* Fix: always load library files before function check

This fixes a critical error in the version handling technique introduced in 2c9c94750d2602b5563ea83cdc0e072fca430844. Because the class files were only loaded by the first sap_initialize_library() function that was defined, multiple active plugins using different versions would lead to cases where the correct version of the library could not be instantiated.
* Add an in-development notice in the readme.md