Follow-up to commit a4867d29c6
- `TILEFLAG_FLIP_HORIZONTAL` -> `TILEFLAG_XFLIP`
- `TILEFLAG_FLIP_VERTICAL` -> `TILEFLAG_YFLIP`
In the previous commit, I pretty much just switched `V` and `H` and
changed the naming a little more to break further uses.
The reason was that the two flags were called counter-intuitively.
Since then, I realized that the auto mapper syntax also already faced
this issue and is already using `XFLIP` and `YFLIP`.
For more consistency and to reduce the amount of names for these flips,
these flags should also be called like that.
It also turned out that more things are connected to `V` and `H`.
Those letters are shown in the `Info` mode in the editor, and are used
extensively by the automapper community.
Switching to `X` and `Y` allows keeping backwards compatibility while
introducing more intuitive names.
be8f6217ce