6rd and 6to4: Replace the three dots in the manpages.
Add support for pptp dialin.
functions.config: Fix call for check function.

If a check function is not available don't crash with an error.
Add missing hook_add to the commands_zone list.
routing: Switch routes priority between ptp and ethernet devices.
headers: Add missing function and rename existing ones.

Add a missing function for hook_add and rename the existing one
to fit the new hook functions layout.
pptp: Add documentation.
Merge remote-tracking branch 'stevee/fixes'
Merge remote-tracking branch 'stevee/man-pages'