Add dims constructor option for Led.Matrix devices
Supports array, object or string e.g.
dims: "16x8"
dims: [16,8]
dims: {columns: 16, rows: 8}
Valid dimensions are 8x8, 16x8 or 8x16
Also make sure led and digit functions in controllers are consistent.
Simplify dims constructor option for Led Matrix
Reverse rows columns in dim opts
Because RowsxColumns seems to be more commonly used than ColumnsxRows
Merge remote-tracking branch 'annagerber/i2cmatrix16x8'

* annagerber/i2cmatrix16x8:
  Reverse rows columns in dim opts Because RowsxColumns seems to be more commonly used than ColumnsxRows
  Simplify dims constructor option for Led Matrix
  Add dims constructor option for Led.Matrix devices Supports array, object or string e.g. dims: "16x8" dims: [16,8] dims: {columns: 16, rows: 8} Valid dimensions are 8x8, 16x8 or 8x16 Also make sure led and digit functions in controllers are consistent.