Orientation: planning

I want to add 'orientation' options;

This enables rotated text, and effects such as mirroring.

* flip (bool) : mirror about the horizontal axis
* simply manipulate the glyph before adding to character framebuffer
* affects the vertical alignment operation for `baseline`, flips `top` and `bottom`
* mirror (bool) : mirror about the vertical axis
* reverse the character print order
* manipulate the glyph before adding to character framebuffer
* flip `left` and `right` horizontal alignment
* twist (bool)
* hardest
* change the print direction
* change the alignment operation (this could get complex)
* manipulate the glyph before adding to character framebuffer (which needs x/y dimensions adjusted to suit)

Changes applied to the alignment by flipping and mirroring, plus the axis swap from twist need to affect be reflected in returns from the `rect()` method (but `size` should be unaffected? I need to think about whether width and height should be swapped when twist is applied?, humm...)