6.0.0
Merge remote-tracking branch 'origin/v6' into feat-matrix-enhance
fix(theme): update v5 theme
feat(matrix & calendar): (1). Support matrix col/row size option. (2). Support corner content options in matrix. (3) Support body content options. (4). Support matrix `mergeCells`. (5). Fix and refactor the matrix style options, conserning their inheritance and z-order and flexibility. (6). Support declaratively layout other components (including grid/polar/geo/graph coord sys, and dataZoom/visualMap/legend/... components) based on `matrix`/`calendar`. And and enhance the echarts API `convertToLayout`/`convertToPixel`, custom series API `api.coord`/`api.coord` to support this feature comprehansively. Considering the previous "pie layout on coord sys", introduce the `boxCooridnateSystem` and `createBoxLayoutReference` to all of the components and echarts for the overall coord sys infrastructure. (7). Add some test cases to matrix and calendar.
refact: make components installable