organize code projects

[realpdm]

Some code is duplicated inside the 'range' project and as their own projects. mod_range is an example of this. The one inside range/mod_range is outdated while the top level mod_range is more recently updated. libcrange is the opposite, the one inside range/libcrange has been updated more recently. Are the two versions diverging? It is a little confusing.

Should each project inside range/ that is being worked on be made its own project?