you can tell, by looking at the package definition. If you look in the device template, you'll see that there is a package called Pluto ZWave.
If you go to advanced > software > packages, you can search on page for Pluto ZWave, and see two packages, one for ZWave and one for ZWave source.
by looking at the package definition for ZWave source, you can see that it's copying things from src/ZWave in the source tree.
Right now, we are building from the LinuxMCE-0810 branch:http://svn.linuxmce.org/svn/branches/LinuxMCE-0810/
so, looking in src/ZWave, will get you all the files related to the driver. There are a few in Gen_Devices relating to ZWave, but these are abstract class definitions required by DCE.