bc-gh: Update to 3.2.7

Note that "DC_ENV_ARGS" will lead to dc exiting; this was new in 3.1.4
and I have reported that upstream.

Upstream changes, less bugfixes (and hence first/second do not make
sense; see the full NEWS.md in the sources if that upsets you):

## 3.2.5

This is a production release that fixes several bugs and adds a couple small
things.

The two most important bugs were bugs that causes `dc` to access memory
out-of-bounds (crash in debug builds). This was found by upgrading to `afl++`
from `afl`. Both were caused by a failure to distinguish between the same two
cases.

Fourth, the pseudo-random number now attempts to seed itself with `/dev/random`
if `/dev/urandom` fails.

## 3.2.0

This is a production release that has one bug fix and a major addition.

The major addition is a way to build a version of `bc`'s math code as a library.
This is done with the `-a` option to `configure.sh`. The API for the library can
be read in `./manuals/bcl.3.md` or `man bcl` once the library is installed with
`make install`.

This library was requested by developers before I even finished version 1.0, but
I could not figure out how to do it until now.

If the library has API breaking changes, the major version of `bc` will be
incremented.

## 3.1.4

This is a production release that fixes one bug, changes two behaviors, and
removes one environment variable.

The behavior that was changed is that `bc` now exits when given `-e`, `-f`,
`--expression` or `--file`. However, if the last one of those is `-f-` (using
`stdin` as the file), `bc` does not exit. If `-f-` exists and is not the last of
the `-e` and `-f` options (and equivalents), `bc` gives a fatal error and exits.

Next, I removed the `BC_EXPR_EXIT` and `DC_EXPR_EXIT` environment variables
since their use is not needed with the behavior change.

Finally, I made it so `bc` does not print the header, though the `-q` and
`--quiet` options were kept for compatibility with GNU `bc`.


(gdt)