libnsutils: use libVersion{,Compat}, fix REQUIRES_devel.
libnsutils: use libVersion{,Compat}, fix REQUIRES_devel.

Also simplify BUILD & INSTALL.

haikuports/haikuports,haikuports/haikuports,moochris/haikuports,Begasus/haikuports,moochris/haikuports,nielx/haikuports,Begasus/haikuports,nielx/haikuports,Begasus/haikuports,haikuports/haikuports,nielx/haikuports,haikuports/haikuports,Begasus/haikuports,moochris/haikuports,Begasus/haikuports,haikuports/haikuports