Makefile:
When installing chibi, make installation directory and install files for SRFI 231.
When uninstalling chibi, remove installation directory and files for SRFI 231.
lib/srfi/231/transforms.scm:
Move definition of vector-iota from here to ...
lib/srfi/231/base.scm:
Here.
lib/srfi/231/base.sld:
Export vector-iota to use in both base.scm and transforms.scm.