Engine: Unescape \[ before calculating wrapped text width

- Removed the unused wouttext_reverseifnecessary function
- Unified right-to-left and left-to-right text output so that they both
use the same splitting function
- Merged removeBackslashBracket into a new unescape function that
handles both [ and \[ (to allow for the following change)
- Fixed display problem by unescaping text before text width is
calculated