Different distributions of doxygen have different default
values of HAVE_DOT setting, so we need to pick a specific
setting to avoid 'missing dot' warnings on some platforms.

Doxygen uses it to generate inclusion graphs for our various
header files, which is somewhat useful, but not essential.
We therefore enable dot if it's present (usually through
the parent graphviz package) but disable it if it's not
available, silencing the warning, but not giving uniform
results.

The set of supported Doxygenfile keys changes from release
to release, often resulting in warnings about needing to
upgrade the configuration file. However, this isn't
practical given the various versions different developers
have installed.

However, for the vast majority of keys we just want the
default values, so instead only include the keys we've
specifically set and let doxygen fall back to defaults
for all the rest.

There is also no trailing whitespace.

Philip Jägenstedt authored 12 years ago and Gregory Maxwell committed 12 years ago

I stumbled upon the typo in README.draft, so took the opportunity to
grep for common misspellings using List_of_common_misspellings.txt for
hunspell.

Gregory Maxwell authored 12 years ago and Jean-Marc Valin committed 12 years ago

Also get the subname rigtht.

Doxygen is a tool for generating programming documentation
based on comments in header and source files. This commit
adds the necessary configuration file and associated support
in the autotools build.

Right now it doesn't generate much documentation because our
public header files aren't marked up. Warnings are printed
for undocumented members and arguments.