Building gravity using distribution-provided libraries is unnecessarily complex and unwelcoming to new users

[chrismurf]

Currently, if you want to download and build gravity as a new user, you cannot just download it and run ./configure, make.

My standard configure line ends up being something along the lines of the below:

./configure --prefix=/usr --with-python=/usr/bin/python3 --with-protoc=/usr/bin/protoc --without-java --with-zeromq-incdir=/usr/include

While the prefix and python are debatable, it would be nice if the out-of-the-box configure was able to find distribution-provided protoc and zeroMQ includes, and didn't include Java (which is not a typical Linux package).