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.
* linespec.c (struct ls_parser): New member keyword_ok.
(linespec_lexer_lex_string): Add comment.
(linespec_lexer_lex_one): Ignore keywords if it's the wrong place
for one.
(parse_linespec): Set keyword_ok.
testsuite/
* gdb.linespec/ls-errs.exp: Change tests of "b if|task|thread".
* gdb.linespec/thread.c: New file.
* gdb.linespec/thread.exp: New file.