* Remove Autotools cruft (`ltmain.sh` and friends) and add to
.gitignore
* No need to add `INSTALL` and `COPYING` to the `doc_DATA` targets.
These files shouldn't be installed, and there is no need to add
them to `doc_DATA`, as Automake will still add them to the tarball.
* Use `AX_PTHREAD`, which is the modern replacement for `ACX_PTHREAD`.
* Do not override `$(docdir)`, which is a user flag and shouldn't
be modified according to GNU conventions.
* Install html files into `$(htmldir)` and not `$(docdir)`.
* Only build tests when they are requested, that is, test targets
should be prefixed with `check_` and not `noinst_`.
* Copy the `.cc` file to `.c` instead of using `$(LN_S)` which breaks
`VPATH` (out-of-source builds).
