| Introduce a level of indirection and versioning in the config files |
| ------------------------------------------------------------------- |
| |
| `config.h` was split into `build_info.h` and `mbedtls_config.h`. |
| `build_info.h` is intended to be included from C code directly, while |
| `mbedtls_config.h` is intended to be edited by end users wishing to |
| change the build configuration, and should generally only be included from |
| `build_info.h`. This is because all the preprocessor logic has been moved |
| into `build_info.h`, including the handling of the `MBEDTLS_CONFIG_FILE` |
| macro. |
| |
| Mandatory version symbols were introduced for `MBEDTLS_CONFIG_FILE` and |
| `MBEDTLS_USER_CONFIG_FILE`, `MBEDTLS_CONFIG_VERSION` and |
| `MBEDTLS_USER_CONFIG_VERSION` respectively. Both config files should include |
| a definiton of their respective version symbol, with a value of `1` to be |
| considered valid. |
