Matlab bindings now only building once rather than every call to make, via the use of some proxies. Matlab build currently only happens in one thread, so it can be pretty slow

modules/matlab/compile.cmake

@@ -0,0 +1,14 @@
+macro(listify OUT_LIST IN_STRING)
+    string(REPLACE " " ";" ${OUT_LIST} ${IN_STRING})
+endmacro()
+
+listify(MEX_INCLUDE_DIRS_LIST ${MEX_INCLUDE_DIRS})
+file(GLOB SOURCE_FILES "${CMAKE_CURRENT_BINARY_DIR}/src/*.cpp")
+foreach(SOURCE_FILE ${SOURCE_FILES})
+    # compile the source file using mex
+    execute_process(
+        COMMAND ${MATLAB_MEX_SCRIPT} ${MEX_OPTS} ${MEX_INCLUDE_DIRS_LIST} 
+                ${MEX_LIB_DIR} ${MEX_LIBS} ${SOURCE_FILE}
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/src
+    )
+endforeach()