Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
Then you can just toggle back and forth with '/'.
One day, these frames should use a tool manager for this
kind of thing (also for the ruler tool, but lots of other
things on top), but for now just bind a char hook.
There was a gentle mish-mash of booleans, some with
true being left/right and some up/down, and some functions that
can flip in both axes (which is never actually done, and doesn't
really make geometric sense).
Replace all this with the FLIP_DIRECTION enum class, which makes
the intention completely unambiguous.
This also then allows a small scattering of simplifications,
because everything takes the same type and you don't have to
fiddle booleans to fit.
(It's still leaking into BOARD_COMMIT and some other places, but at
least it no longer leaks into all the edit tools.)
Also fixes some bugs when moving/copying/pasting multiple selections
containing length-tuning patterns.
Moves forced-transparency setting down into VIEW_ITEM so that it can
be used to place forced-transparent objects in a different target.
This keeps EnableDepthTest() from equalizing the alpha values between
the two symbols (or two footprints).
