include capistrano receipes for ferret index and server maintenance

See also #190.

my rake task: http://pastie.textmate.org/private/4xyk2o0obibzi2tmpbog

my capistrano tasks:

namespace :ferret do
  desc "Stop the Ferret server, and continue even if the operation fails."
  task :stop_safe, :roles => :app, :on_error => :continue do
    top.ferret.stop
  end

  desc "Start Ferret Server"
  task :start, :roles => :app do
    top.ferret.start
  end

  desc "Stop Ferret Server"
  task :stop, :roles => :app do
    top.ferret.stop
  end

  desc "Restart Ferret Server"
  task :restart, :roles => :app do
    top.ferret.restart
  end

  desc "Rebuild the Ferret index"
  task :rebuild, :roles => :app do
    run "cd #{current_path} && rake production ferret:rebuild"
  end

  desc "Destroy the Ferret index"
  task :destroy, :roles => :app do
    run "cd #{current_path} && rm -rf index/production index/development index/test"
  end

end

added a generic rebuild rake task as well as some capistrano recipes for starting/stopping DRb and index maintenance in production environments.