Log Message:
Update to 2.22

Changelog:
* Noteworthy changes in release 2.22 (2015-11-01) [stable]

** Improvements

  Performance has improved for patterns containing very long strings,
  reducing preprocessing time for an N-byte regexp from O(N^2) to
  only slightly superlinear for most patterns.  Before, a command like
  the following would take over a minute, but now, it takes less than
  a second:
  : | grep -f <(seq -s '' 99999)

  When building grep, 'configure' now uses PCRE's pkg-config module for
  configuration information, rather than attempting to guess it by hand.

** Bug fixes

  A DFA matcher bug made this command mistakenly print its input line:
    echo axb | grep -E '^x|x$'
  Likewise for this equivalent command:
    echo axb | grep -e '^x' -e 'x$'
  [bug introduced in grep-2.19 ]

  grep no longer reads from uninitialized memory or from beyond the end
  of the heap-allocated input buffer.  This fix addressed CVE-2015-1345.
  [bug introduced in grep-2.19 ]

  With -z, '.' and '[^x]' in a pattern now consistently match newline.
  Previously, they sometimes matched newline, and sometimes did not.
  [bug introduced in grep-2.4]

  When the JIT stack is exhausted, grep -P now grows the stack rather
  than reporting an internal PCRE error.

  'grep -D skip PATTERN FILE' no longer hangs if FILE is a fifo.
  [bug introduced in grep-2.12]

  --exclude and related options are now matched against entire
  command-line arguments, not against command-line components.
  [bug introduced in grep-2.6]

  Fix performance degradation of grep -Fw in unibyte locales.
  [bug introduced in grep-2.19 ]