message: Make error message more informative when github tarball is downloaded, which doesn't include csocket.
  See
diff: @@ -242,9 +242,21 @@ endif()
  file(GLOB csocket_files LIST_DIRECTORIES FALSE
  "${PROJECT_SOURCE_DIR}/third_party/Csocket/Csocket.*")
  if(csocket_files STREQUAL "")
  - message(FATAL_ERROR " It looks like git submodules are not initialized.\n"
  + execute_process(COMMAND git status
  + WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
  + RESULT_VARIABLE git_status_var
  + OUTPUT_QUIET
  + ERROR_QUIET)
  + if(git_status_var)
  + message(FATAL_ERROR
  + " It looks like git submodules are not initialized.\n"
  + " Either this is not a git clone, or you don't have git installed")
  + else()
  + message(FATAL_ERROR
  + " It looks like git submodules are not initialized.\n"
  " Run: git submodule update --init --recursive")
  endif()
  +endif()
  install(DIRECTORY webskins
  DESTINATION "${CMAKE_INSTALL_DATADIR}/znc")
  