Whenever a change is made to the classad library code that would break binary compatibility,
the version of the classad library needs to be bumped. To do this, open CMakeLists.txt from
this dirctory, and search for SOVERSION in a line that looks like this:

	set_target_properties( classad PROPERTIES VERSION ${PACKAGE_VERSION} SOVERSION 6 )

The classad library version is the number 6 above. Increment it to indicate that code built
with earlier versions of the classad header files should not be linked with this version.
