Upgrade perl-current to 5.6.0. Changes:

Upgrade perl-current to 5.6.0. Changes:

 *  Interpreter cloning, threads, and concurrency
 *  Lexically scoped warning categories
 *  Unicode and UTF-8 support
 *  Support for interpolating named characters
 *  "our" declarations
 *  Support for strings represented as a vector of ordinals
 *  Improved Perl version numbering system
 *  New syntax for declaring subroutine attributes
 *  File and directory handles can be autovivified
 *  open() with more than two arguments
 *  64-bit support
 *  Large file support
 *  Long doubles
 *  "more bits"
 *  Enhanced support for sort() subroutines
 *  C<sort $coderef @foo> allowed
 *  File globbing implemented internally
 *  POSIX character class syntax [: :] supported
 *  Improved C<qw//> operator
 *  pack() format 'Z' supported
 *  pack() format modifier '!' supported
 *  pack() and unpack() support counted strings
 *  Comments in pack() templates
 *  Weak references
 *  Binary numbers supported
 *  Lvalue subroutines
 *  Some arrows may be omitted in calls through references
 *  Boolean assignment operators are legal lvalues
 *  exists() is supported on subroutine names
 *  exists() and delete() are supported on array elements
 *  Pseudo-hashes work better
 *  Automatic flushing of output buffers
 *  Better diagnostics on meaningless filehandle operations
 *  Where possible, buffered data discarded from duped input filehandle
 *  eof() has the same old magic as <>
 *  binmode() can be used to set :crlf and :raw modes
 *  C<-T> filetest recognizes UTF-8 encoded files as "text"
 *  system(), backticks and pipe open now reflect exec() failure
 *  Improved diagnostics
 *  Diagnostics follow STDERR
 *  syswrite() ease-of-use
 *  Better syntax checks on parenthesized unary operators
 *  Bit operators support full native integer width
 *  Improved security features
 *  C<require> and C<do> may be overridden
 *  $^X variables may now have names longer than one character
 *  New variable $^C reflects C<-c> switch
 *  New variable $^V contains Perl version as a string
 *  Optional Y2K warnings
 *  Modules
 *  Pragmata
 *  dprofpp
 *  find2perl
 *  h2xs
 *  perlcc
 *  perldoc
 *  The Perl Debugger
 *  Simple sort() using { $a <=> $b } and the like are optimized
 *  Optimized assignments to lexical variables
 *  Faster subroutine calls
 *  -Dusethreads means something different
 *  New Configure flags
 *  Threadedness and 64-bitness now more daring
 *  Long Doubles
    ...

See 'perldoc perldelta' for a full list.