We set a dedicated route to reach the VPN gateway only if the parent
device has a gateway. If the parent device doesn't have a gateway (for
example in case of GSM connections) and the VPN gets the default
route, the VPN gateway will be contacted through the VPN itself, which
obviously doesn't work.
Set up a device route if the parent device doesn't provide a gateway.
https://bugzilla.redhat.com/show_bug.cgi?id=1403660
This makes it easier to install the files with proper names.
Also, it makes the makefile rules slightly simpler.
Lastly, the documentation is now generated into docs/api, which makes it
possible to get rid of the awkward relative file names in docbook.
Keep the include paths clean and separate. We use directories to group source
files together. That makes sense (I guess), but then we should use this
grouping also when including files. Thus require to #include files with their
path relative to "src/".
Also, we build various artifacts from the "src/" tree. Instead of having
individual CFLAGS for each artifact in Makefile.am, the CFLAGS should be
unified. Previously, the CFLAGS for each artifact differ and are inconsistent
in which paths they add to the search path. Fix the inconsistency by just
don't add the paths at all.
