Add a small TOC entry for the DDOX based docs as an alternative to the normal ones.
Update DDOX resource for the latest version (new icons and search support).
Reduce font size for search results.
Properly integrate the "apidocs" targets with "all" and let DUB keep the "dpl-docs" tool up to date.

Also keeps the line length to 80 characters and adds missing resource files to posix.mak.