update: add asset importer lib cmake find macro.

cmake-modules/Findassimp.cmake

@@ -0,0 +1,25 @@
+FIND_PATH(
+	assimp_INCLUDE_DIRS
+	NAMES postprocess.h scene.h version.h config.h cimport.h
+	PATHS /usr/local/include/btr-headers
+)
+
+FIND_LIBRARY(
+	assimp_LIBRARIES
+	NAMES assimp
+	PATHS /usr/local/lib/
+)
+
+IF (assimp_INCLUDE_DIRS AND assimp_LIBRARIES)
+    SET(assimp_FOUND TRUE)
+ENDIF (assimp_INCLUDE_DIRS AND assimp_LIBRARIES)
+
+IF (assimp_FOUND)
+    IF (NOT assimp_FIND_QUIETLY)
+        MESSAGE(STATUS "Found asset importer library: ${assimp_LIBRARIES}")
+    ENDIF (NOT assimp_FIND_QUIETLY)
+ELSE (assimp_FOUND)
+    IF (assimp_FIND_REQUIRED)
+        MESSAGE(FATAL_ERROR "Could not find asset importer library")
+    ENDIF (assimp_FIND_REQUIRED)
+ENDIF (assimp_FOUND)