This fixes standalone when those libraries are installed
elsewhere. Note that it "breaks" standalone if you just
installed the prebuilt manually. For that to work you
have to add /.../libraries/include to CMAKE_INCLUDE_PATH,
which is not recommended because it would pick up any
other prebuilt over your system installed libraries.
Instead, for standalone, install the libraries somewhere
with some prefix and then add that prefix to the environment
variable CMAKE_PREFIX_PATH.
For example, $prefix/include/collada and $prefix/lib/libcollada4dom.so
