[CMake] cget: cmake package retrieval

[paul Fultz]

Hello All,

I have written a tool that I didn't know if people in the CMake community
might be interested in, called CGet that will retrieve and install packages
with CMake:

https://github.com/pfultz2/cget

This will download a package and run the CMake build and install on the
package. It can even download the dependencies if they are listed in a
requirements.txt.

Also, it doesn't require changes to the CMake to integrate with CGet. So it
can already install lots of packages already. For example, the ZLib library
can be installed directly like this:

cget install http://zlib.net/zlib-1.2.8.tar.gz

Tests for a CMake package can be ran as well:

cget install --test http://zlib.net/zlib-1.2.8.tar.gz

In the future, I am planning to support the idea of "channels". A channel is a
list of CMake packages but provides additional metadata about the package such
as version number, or checksums. This will allow better versioning constraints
when using packages.

Any feedback or comments about this would be great.

Thanks,
Paul