randrproto, inputproto and PKG_CONFIG_PATH for build

[Ted X Toth]

The current build requires randrproto 1.2 and inputproto 1.4. When I 
installed these they get installed to /usr/local/lib/pkgconfig. So in 
order to get the build to work I have to set PKG_CONFIG_PATH to 
/usr/local/lib/pkgconfig:/usr/lib/pkgconfig. Is this the right way to 
handle multiple versions of inputproto and randrproto? Does this cause 
any unwanted side affects like bad rpaths in shared libraries?