unpack/relocate textures to a folder other than ./texture

If I unpack a blender file, it creates a folder called "texture", that is within the current folder. Instead I'd like to default the unpack to a folder the is common across many 3d applications that I use (example: Documents/3d/textures). I might be overlooking a Preferences setting.

This could also help me migrate previous blend files that might have used some other folder structure (pack and then unpack to my new structure).