Two new issues arising from 2.1.
* The branch preview is inherently left to right. When we open branching in a RTL format, we flip the doors over, so that the sequences are drawn right to left, but when we minimise branching and the icon is updated to "preview" the flow, the preview is shown running left to right. This is due to the preview not paying an actual attention to how the branching is drawn (which would be an awful lot of work).
* Optional sequences work left to right.