new packages in wip (frr, libyang)

[Frank Kardel <kardel%netbsd.org@localhost>]

Hi !

I create two packages in wip.
	- libyang - YANG data modeling language library
		(prerequisite for the frr package)
	- frr - FRRouting - a more actively maintained and advanced
		fork of the quagga routing suite

Maybe somebody wants to look at these packages.

There is a little build error in the makeinfo part due to
image files not being at the right build location. This seems
to be a genuine frr bug. Maybe somebody can dig out a fix for that.

I'd like to move the packages over to pkgsrc in about a week unless
something unexpected happens.

Thanks!
  Frank