Make doctools optional
Review Request #125612 - Created Oct. 12, 2015 and submitted
Make doctools optional to avoid needing them just to deploy kservice on win/mac.
If this is OK for this framework, I would apply the same logic to others, too.
doctools is all nice, but just for getting the libraries built it is a bit heavy, given nothing of its dependencies ships with Windows.
make install did still create docs if doctools is around