lib/hens/gem.rake: Renamed :ruby_versions to :cross_ruby_versions.
lib/hens/gem.rake: Default RUBY_CC_VERSION to all versions defined in rake-compiler config.
lib/hens/gem.rake: Set :cross_compile default depending on :cross_config_options.
lib/hens/gem.rake: Added support for with_cross_<library> options.
lib/hens/gem.rake: Added support for :cross_compiling option.
lib/hens/gem.rake: Added support for :local_files option.
lib/hens/gem.rake: Ignore first part "ruby" for ext_name.
lib/hen.rb (lay!): Enable full backtrace when Rake tracing enabled.
lib/hen.rb: Load 'rake/clean' for convenience.
v0.8.1