message: Use taged versions of external libraries
diff: @@ -85,7 +85,7 @@ set(YAMLCPP_GIT_URL "https://github.com/jbeder/yaml-cpp.git" CACHE STRING "URL t
  ExternalProject_Add(YAMLCPP
  PREFIX ${YAMLCPP_PREFIX}
  GIT_REPOSITORY ${YAMLCPP_GIT_URL}
  - UPDATE_COMMAND ${GIT_EXECUTABLE} pull
  + GIT_TAG beb44b872c07c74556314e730c6f20a00b32e8e5
  INSTALL_DIR ${YAMLCPP_INSTALL_DIR}
  CMAKE_ARGS ${YAMLCPP_CMAKE_ARGS}
  LOG_DOWNLOAD ON
  @@ -107,8 +107,8 @@ set(CATCH_GIT_URL https://github.com/philsquared/Catch.git CACHE STRING "URL to
  ExternalProject_Add(catch
  PREFIX ${CATCH_PREFIX}
  GIT_REPOSITORY ${CATCH_GIT_URL}
  + GIT_TAG "v1.10.0"
  TIMEOUT 10
  - UPDATE_COMMAND ${GIT_EXECUTABLE} pull
  CONFIGURE_COMMAND ""
  BUILD_COMMAND ""
  INSTALL_COMMAND ""
  @@ -128,8 +128,8 @@ if (WIN32)
  ExternalProject_Add(dirent
  PREFIX ${DIRENT_PREFIX}
  GIT_REPOSITORY ${DIRENT_GIT_URL}
  + GIT_TAG "1.22"
  TIMEOUT 10
  - UPDATE_COMMAND ${GIT_EXECUTABLE} pull
  CONFIGURE_COMMAND ""
  BUILD_COMMAND ""
  INSTALL_COMMAND ""
  