v2.9.0

• after declaring \mplibcodeinherit{enable}, each mplib code chunks will inherit variables/constants/macros defined by previous chunks. On the contrary, the default (and backward-compatible) value \mplibcodeinherit{disable} will treat each code chunks as an independent instance, never being affected by other code chunks.
• It does not work to pass picture variables containing btex ... etex elements, as these are not METAPOST, but TeX elements from the standpoint of luamplib. Likewise, you cannot use graph.mp with the inheritance functionality.