message: Allow overriding CMAKE_INSTALL_PREFIX.
  Still results in ${CMAKE_INSTALL_PREFIX}/usr/bin/eosio*
diff: @@ -4,7 +4,9 @@ install_directory_permissions( DIRECTORY usr/include/eosio )
  set(CPACK_PACKAGE_CONTACT "support@block.one")
  set(CPACK_OUTPUT_FILE_PREFIX ${CMAKE_BINARY_DIR}/packages)
  +if(NOT DEFINED CMAKE_INSTALL_PREFIX)
  set(CMAKE_INSTALL_PREFIX ${CMAKE_BINARY_DIR}/install)
  +endif()
  SET(CPACK_PACKAGE_DIRECTORY "${CMAKE_INSTALL_PREFIX}")
  set(CPACK_PACKAGE_NAME "EOS.IO")
  