* gcov.c: Comments updated.
(source_info): Add file_time field.
(source_index): New variable.
(mutiple_files): New variable.
(generate_results): New function extracted from process_file.
(process_file): Save and restore chain of functions, generate
results and free structures only if not merging results.
(release_structures): File names are now freed in create_file_names
(create_file_names): Free previous file names.
(find_source): File date is now read here and modifications in
source files is checked here.
(read_graph_file): Only reverse order of functions for the current
object file.
(make_gcov_file_name): Do not generate long names if input_name is
NULL.
(output_lines): If merging results do not display graph, data and
runs informations.
Checking source file modification is done in find_source.
* doc/gcov.texi: Append an s to sourcefile.
From-SVN: r125649
