Update pygments to 1.3.1.
While here, fixes(?) LICENSE from modified-bsd to 2-clause-bsd.

Version 1.3.1
-------------
(bugfix release, released Mar 05, 2010)

- The ``pygmentize`` script was missing from the distribution.

Version 1.3
-----------
(codename Schneegl旦ckchen, released Mar 01, 2010)

- Added the ``ensurenl`` lexer option, which can be used to suppress the
  automatic addition of a newline to the lexer input.

- Lexers added:

  * Ada
  * Coldfusion
  * Modula-2
  * haXe
  * R console
  * Objective-J
  * Haml and Sass
  * CoffeeScript

- Enhanced reStructuredText highlighting.

- Added support for PHP 5.3 namespaces in the PHP lexer.

- Added a bash completion script for `pygmentize`, to the external/
  directory (#466).

- Fixed a bug in `do_insertions()` used for multi-lexer languages.

- Fixed a Ruby regex highlighting bug (#476).

- Fixed regex highlighting bugs in Perl lexer (#258).

- Add small enhancements to the C lexer (#467) and Bash lexer (#469).

- Small fixes for the Tcl, Debian control file, Nginx config,
  Smalltalk, Objective-C, Clojure, Lua lexers.

- Gherkin lexer: Fixed single apostrophe bug and added new i18n keywords.

(obache)