Some are doxy comments, some are just trivial source comment typos.
Found using `codespell -q 3 --skip="./contrib" -I ../assimp-whitelist.txt`
whereby whitelist contained:
```
childs
iff
lod
nto
ot
whitespaces
```
Current documentation lacks a proper directory handling and switch for
Unix like systems.
The option BUILD_DOCS are added as disable by default, even so the
Doxyfile file is generated for a manual build.
Option HTML_OUTPUT are made cached to be properly replaced, as usually
done by some Linux distributions
Microsoft CHM option is enabled if MSVC is detected.
