Build instructions on building glog from source are no longer correct

[CaptJak]

https://github.com/google/glog no longer contains the 'configure' script, but instead provides instructions for cmake to build and install.

i.e.

cd glog
./configure # add --with-gflags=whereyouinstalledgflags
# to avoid ERROR: unknown command line flag 'minloglevel' later
make -j && sudo make install

is incorrect unless you're using an older version of glog. glog-0.3.5 still has the configure script and works without problem.