adding include of openssl/err.h to fix errors when NO_SSL_DL is defined:

mongoose.c:4680:23: error: ‘ERR_get_error’ was not declared in this scope
mongoose.c:4681:52: error: ‘ERR_error_string’ was not declared in this scope

Added check for document_root != NULL in convert_uri_to_file_name(). Added #define rmdir _rmdir for win32

Fix uninitialized argument in getsockname().

Always use absolute path for document_root. If relative path is used, it is relative to mongoose.exe directory. See https://github.com/valenok/mongoose/issues/181

Allow no SSL_CERTIFICATE when using init_ssl callback.