WIP: Rewritten man page indexer in Rust

Currently just figuring out how to read archives. Turns out to not be as
simple as I had expected.

indexer/tests/mktar.sh

@@ -0,0 +1,49 @@
+#!/bin/sh
+
+# The order of inserting the files into the tar is not fully deterministic this
+# way.  The tests will fail quite badly if hardlink.6 is considered the
+# "original" version.
+
+mkdir man
+cd man
+
+mkdir man1
+mkdir man3
+mkdir man6
+ln -s man3 mans
+
+echo 'Hello World' >man3/helloworld.3
+echo 'Not a very interesting file' >notinteresting
+echo 'Potentially interesting file' >possiblyinteresting
+
+ln man3/helloworld.3 man6/hardlink.6
+
+ln -s ../man3/helloworld.3 man1/symlinkbefore.1
+ln -s ../man3/helloworld.3 man6/symlinkafter.6
+
+ln -s notadir/../../man3/helloworld.3 man1/badsymlink1.1
+ln -s man3/helloworld.3 man1/badsymlink2.1
+ln -s ../man3/helloworld.3/. man1/badsymlink3.1
+ln -s ../man3/helloworld.3/../helloworld.3 man1/badsymlink4.1
+ln -s ../man1/symlinkbefore.1/../../man1/helloworld.3 man1/badsymlink5.1
+
+ln -s symlinkbefore.1 man1/doublesymlink1.1
+ln -s ../mans/helloworld.3 man1/doublesymlink2.1
+ln -s ../mans/../man1/symlinkbefore.1 man1/triplesymlink.1
+ln -s infinitesymlink.1 man1/infinitesymlink.1
+
+ln -s ../possiblyinteresting man3/needreread.3
+ln -s ../possiblyinteresting man6/needreread.6
+
+cd ..
+rm -f testarchive.tar
+tar -cf testarchive.tar man/
+rm -r man/
+
+mkdir man
+echo 'Overwritten file' >man/possiblyinteresting
+tar -rf testarchive.tar man/
+rm -r man/
+
+rm -f testarchive.tar.xz
+xz testarchive.tar