Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* memrange.c (compare_mem_ranges): Mention sort order in
describing comment.
(normalize_mem_ranges): Add comment. Fix ra->length calculation.
* tracepoint.c (traceframe_available_memory): Extend comment to
mention what happens to RESULT when the target does not support
the query.
