* Add preferences for tile mode basis vectors
Each tile is offset according to the x and y basis. For example, a tile (1,1) would be at basis_x + basis_y
* Update tools for custom tile modes
Show the indicator in the correct position, and only draw on the nearest tile.
* Fix style issues
* Move tile functionality to own class to prevent bloating Project
* Fix error in Tiles bounding box logic
* Make tile mode offsets project settings
Since the desired tile mode offsets depends on the tile being drawn, the tile mode offsets should be a project specific setting which is persisted in the project file.
* Update TileMode object immediately after closing dialog
* Don't draw center tile by default in TileMode
* Move tile mode offsets to view menu
* Move tile mode offsets dialog out of ImageEffects
