There were two issues with the unit extraction regex:
- it didn't take the inches, feet, arcminutes and arcseconds symbols
into accounts, which aren’t letters but ' and ";
- some units have more than one B_UNIT_DEF_* flag.
This allows extracting feet, inches, square millimeters, cubic
millimeters, arcminutes, and arcseconds.
Reviewed By: mont29
Differential Revision: https://developer.blender.org/D16144
fd48f1b505