* module/ice-9/boot-9.scm (<parameter>, make-parameter, parameter?)
(parameter-fluid, parameter-converter, parameterize): New top-level
bindings, implementing SRFI-39 parameters. Currently,
current-input-port and similar procedures are not yet parameters.
* test-suite/Makefile.am:
* test-suite/tests/parameters.test: Add tests, taken from srfi-39
tests.
