input/Plugin: migrate init() from class Error to C++ exceptions

test/dump_text_file.cxx

@@ -31,6 +31,8 @@
 #include "archive/ArchiveList.hxx"
 #endif
 
+#include <stdexcept>
+
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -63,7 +65,7 @@ dump_input_stream(InputStreamPtr &&is)
 }
 
 int main(int argc, char **argv)
-{
+try {
 	int ret;
 
 	if (argc != 2) {
@@ -82,10 +84,7 @@ int main(int argc, char **argv)
 #endif
 
 	Error error;
-	if (!input_stream_global_init(error)) {
-		LogError(error);
-		return 2;
-	}
+	input_stream_global_init();
 
 	/* open the stream and dump it */
 
@@ -116,4 +115,7 @@ int main(int argc, char **argv)
 	config_global_finish();
 
 	return ret;
+} catch (const std::exception &e) {
+	LogError(e);
+	return EXIT_FAILURE;
 }