Fix CMake dependencies

Some odd quirks with CMake mean that marias3 has to be in the top level
CMake. Also made submodule checkout happen at cmake time.

utils/libmarias3/CMakeLists.txt

@@ -1,5 +1,21 @@
 set(S3API_DIR ${CMAKE_CURRENT_SOURCE_DIR}/libmarias3 CACHE INTERNAL "S3API_DIR")
 
+find_package(Git QUIET)
+
+if(GIT_FOUND)
+# Update submodules as needed
+    option(GIT_SUBMODULE "Check submodules during build" ON)
+    if(GIT_SUBMODULE)
+        message(STATUS "Submodule update")
+        execute_process(COMMAND ${GIT_EXECUTABLE} submodule update --init --recursive
+			WORKING_DIRECTORY ${S3API_DIR}
+                        RESULT_VARIABLE GIT_SUBMOD_RESULT)
+        if(NOT GIT_SUBMOD_RESULT EQUAL "0")
+            message(FATAL_ERROR "git submodule update --init failed with ${GIT_SUBMOD_RESULT}, please checkout submodules")
+        endif()
+    endif()
+endif()
+
 include(ExternalProject)
 ExternalProject_Add(ms3
     DOWNLOAD_COMMAND cd ${CMAKE_SOURCE_DIR} && git submodule update --init
@@ -9,10 +25,6 @@ ExternalProject_Add(ms3
     EXCLUDE_FROM_ALL TRUE
 )
 
-add_library(marias3 SHARED IMPORTED)
-set_target_properties(marias3 PROPERTIES IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/lib/libmarias3.so.3.1.2)
-add_dependencies(marias3 ms3)
-
 set(S3API_DEPS marias3 curl xml2 CACHE INTERNAL "S3API_DEPS")
 
 install(PROGRAMS