Requirements for CUDD not documented

[TomMD]

The need for CUDD (presumably this) is not documented. More, CUDD has all-but-disappeared from the internet.

Following the build steps yeids:

$ cmake ..
-- GMP library: /usr/lib/x86_64-linux-gnu/libgmp.so
-- Could NOT find CUDD (missing: CUDD_LIBRARY CUDD_INCLUDE_DIR) (Required is at least version "3.0.0")
CMake Error at CMakeLists.txt:52 (message):
  Could not find the Cudd library


-- Configuring incomplete, errors occurred!
See also "/home/admin/dev/sally/build/CMakeFiles/CMakeOutput.log".
See also "/home/admin/dev/sally/build/CMakeFiles/CMakeError.log".