Clean up .gitignore.

* .gitignore: Remove old '/bin' entries; sort lines; and make things
absolute where that makes sense.

.gitignore

@@ -1,52 +1,28 @@
 *.go
 *.log
+*.trs
 *~
 /.config.make
-/bin/basename
-/bin/bash
-/bin/cat
-/bin/chmod
-/bin/compress
-/bin/cp
-/bin/dirname
-/bin/find
-/bin/grep
-/bin/ls
-/bin/mkdir
-/bin/mv
-/bin/reboot
-/bin/rm
-/bin/rmdir
-/bin/sed
-/bin/sh
-/bin/tar
-/bin/touch
-/bin/tr
-/bin/wc
-/bin/which
+/aclocal.m4
+/autom4te.cache/*
+/build-aux/*
+!/build-aux/git-version-gen
+!/build-aux/gitlab-ci.yml
+/config.log
+/config.status
+/configure
+/coverage/*
 /doc/version.texi
 /gash/config.scm
+/lcov.info
 /pre-inst-env
+/pre-inst-env
+/scripts/gash
 /tests/*.1
 /tests/*.2
-/tests/*.log
+/tests/spec/oil
+/tests/spec/oil-link
+/tests/unit/config.scm
+/tools/coverage
 Makefile
 Makefile.in
-aclocal.m4
-autom4te.cache/*
-build-aux/*
-!build-aux/git-version-gen
-!build-aux/gitlab-ci.yml
-config.log
-config.status
-configure
-coverage/*
-lcov.info
-pre-inst-env
-scripts/gash
-tests/*.trs
-tests/spec/oil
-tests/spec/oil-link
-tests/unit/*.trs
-tests/unit/config.scm
-tools/coverage