oxidize: Prep directory structure for Rust translation

- Keeps: `lib`, `tool`
- Deletes everything else except for `COPYING` (i.e. license)
- Replaces `.gitignore` with a more standard Rust one

.gitignore

@@ -1,124 +1,2 @@
-.deps/
-.vagrant/
-Makefile
-Makefile.in
-aclocal.m4
-autom4te.cache/
-config.log
-config.status
-configure
-doxygen-doc/
-libtool
-m4/libtool.m4
-m4/ltoptions.m4
-m4/ltsugar.m4
-m4/ltversion.m4
-m4/lt~obsolete.m4
-*.c~
-*.h~
-*.plist
-.libs
-ChangeLog
-build-aux/ar-lib
-build-aux/compile
-build-aux/config.guess
-build-aux/config.sub
-build-aux/depcomp
-build-aux/install-sh
-build-aux/ltmain.sh
-build-aux/missing
-build-aux/test-driver
-GPATH
-GRTAGS
-GTAGS
-tmp32/
-tmp64/
-yubico-piv-tool-*-win32.zip
-yubico-piv-tool-*-win32.zip.sig
-yubico-piv-tool-*-win64.zip
-yubico-piv-tool-*-win64.zip.sig
-yubico-piv-tool-*.tar.gz
-yubico-piv-tool-*.tar.gz.sig
-yubico-piv-tool-*-mac.zip
-yubico-piv-tool-*-mac.zip.sig
-lib/tests/api
-lib/tests/api.log
-lib/tests/api.o
-lib/tests/api.trs
-lib/tests/basic
-lib/tests/basic.log
-lib/tests/basic.o
-lib/tests/basic.trs
-lib/tests/parse_key
-lib/tests/parse_key.log
-lib/tests/parse_key.o
-lib/tests/parse_key.trs
-lib/tests/test-suite.log
-lib/error.lo
-lib/error.o
-lib/internal.la
-lib/internal.lo
-lib/internal.o
-lib/libykpiv.la
-lib/util.la
-lib/util.lo
-lib/util.o
-lib/version.lo
-lib/version.o
-lib/ykpiv-version.h
-lib/ykpiv.lo
-lib/ykpiv.o
-lib/ykpiv.pc
-lib/.libs/
-tool/cmdline.c
-tool/cmdline.h
-tool/cmdline.o
-tool/yubico-piv-tool
-tool/yubico-piv-tool.1
-tool/yubico-piv-tool.exe
-tool/yubico-piv-tool.o
-tool/.libs/
-tool/libpiv_cmd.la
-tool/libpiv_cmd_la-cmdline.lo
-tool/libpiv_cmd_la-cmdline.o
-tool/libpiv_util.la
-tool/openssl-compat.lo
-tool/openssl-compat.o
-tool/util.lo
-tool/util.o
-tool/tests/cert_9a.pem
-tool/tests/cert_9e.pem
-tool/tests/basic.sh.log
-tool/tests/basic.sh.trs
-tool/tests/key_9a.pub
-tool/tests/parse_name
-tool/tests/parse_name.log
-tool/tests/parse_name.o
-tool/tests/parse_name.trs
-tool/tests/req_9e.pem
-tool/tests/test_inout
-tool/tests/test_inout.log
-tool/tests/test_inout.o
-tool/tests/test_inout.trs
-tool/tests/test-suite.log
-coverage/
-lib/error.gcno
-lib/version.gcno
-lib/ykpiv.gcno
-tool/util.gcno
-tool/yubico-piv-tool.gcda
-tool/yubico-piv-tool.gcno
-ykcs11/.libs/
-ykcs11/*.o
-ykcs11/*.lo
-ykcs11/ykcs11.pc
-ykcs11/libykcs11.la
-ykcs11/ykcs11-version.h
-ykcs11/tests/reset.sh.log
-ykcs11/tests/reset.sh.trs
-ykcs11/tests/test-suite.log
-ykcs11/tests/ykcs11_tests
-ykcs11/tests/ykcs11_tests.log
-ykcs11/tests/ykcs11_tests.o
-ykcs11/tests/ykcs11_tests.trs
-yubico-piv-tool.1.txt
+/target
+**/*.rs.bk