Add quick links on wiki for viewing branch differences easily.
Also fix url markup under "Hacking" heading
Minor edits to make man page more generic (reduce diff with DF branch)
Add PKG_REPO_FROM_HOST (default no) to build repo from host due to some SSH/DNSSEC needs on builders
Fix losing deps in pkg_get_dep_origin.

Regression from [d7ee482581]
Merge multi head