Enable building LRez with cmake

[milot-mirdita]

CMake gets a bit of a bad rep, but it makes building a project like this extremely easy on any platform.

You can now do

mkdir build && cd build 
cmake -DCMAKE_INSTALL_PREFIX=prefix .. 
make

and it will work basically anywhere.

Hope this helps with the conda issue.

[milot-mirdita]

The corresponding conda build.sh file should look like this:

#!/bin/bash
git submodule update --init
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX="${PREFIX}" ..
make -j${CPU_COUNT} ${VERBOSE_CM}
make install