Update to 6.5:

Version 6.5 - June 10 2015

[CHANGES]
New facilities:
o global: New -N (--nearness=[start]) option.
        Nearness sort method is available for the output of tag search command.
The result of nearness sort is concatenation of the followings ([1]-[n])
in this order. The default of 'start' is the current directory.
        [1] Output of local search in the 'start' directory.
        [2] Output of local search in the parent directory except for [1].
        [3] Output of local search in the grandparent directory except for [1]-[2].
        (repeat until the project root directory)
        [n] Output of local search in the project root directory except for [1]-[n-1].
        In each directory, they are sorted by alphabetical order.
o global: Now the --literal option also works with the tag search command,
        -P command and -I command as well as the -g command.

[FIXED BUGS]
o htags: The -c and -x option of htags(1) were still available in the help
  message, even though they had actually been removed. Now, these options
  are removed completely.
o gtags (PHP): Against the following source code, gtags(1) aborted with a message
  'short of memory'. Now it works.
        [nullstring.php]
        +----------------
        |<?php
        |define('');
        |?>
        +----------------
o gtags (C++): Gtags(1) didn't recognize the shift operator. Now it works.
        [a.hh]
        +----------------
        |class const_mod<uint64_t(1) << 48>
        |{
        |};
        +----------------
        $ gtags
        gtags: failed to parse template [+1 ./a.hh].
o gtags (C, C++): Gtags(1) couldn't pick up 'E2' as a definition. Now it works.
        [test.c]
        +----------------
        |enum my_enum2
        |{
        |    E2
        |};
        +----------------

(wiz)