Add one more path to find collada-dom

This is a default path when collada-dom is built as following:
cmake -D CMAKE_INSTALL_PREFIX=install .
cmake --build .
cmake --install .

Author: elsid

CMakeModules/FindCOLLADA.cmake

@@ -64,6 +64,7 @@ FIND_PATH(COLLADA_INCLUDE_DIR dae.h
     ${COLLADA_DOM_ROOT}/include
     $ENV{COLLADA_DIR}/include
     $ENV{COLLADA_DIR}
+    $ENV{COLLADA_DIR}/include/collada-dom2.5
     ~/Library/Frameworks
     /Library/Frameworks
     /opt/local/Library/Frameworks #macports