Upgrade parrot from version 2.5.0 to 2.6.0.

Pkgsrc changes:
o Adapt to new content being installed (PLIST) and new perl script
  which needs tweaking.

Upstream changes:

- Core
  + Plug some memory leaks
  + As always, bug fixes and some optimizations
- Runtime
  + added (experimental) URI::Escape
- Testing
  + Improved test coverage of core parrot
- Documentation
  + Updated the Squaak tutorial to use modern NQP-rx and PCT
- Platforms
  + The Fedora package 'parrot-devel' install the files for syntax-highlighting
    and automatic indenting for the vim editor
- NQP-rx
  + Updated version included from http://github.com/perl6/nqp-rx includes
    new or improved: regex backtracking, named assertions, interactive mode,
    and setting (a minimal but useful runtime library)

(he)