recursive arrays & sort methods
Update array.rb
Add gem version to README
Merge pull request #241 from fntzr/sort

Update Array#sort method and Array#== method.
Add Opal::Environment for wrapping internal sprockets logic
Fix Opal::process() to use correct environment
Add $window and $global as aliases for Native.global
Add `$document` gvar if it exists on $window
Native#method_missing() now tries to convert each argument to native by #to_native.
Native#method_missing uses Array#to_native to convert arguments
Add native example of dom manipulation
Method missing dispatcher raises error if object does not implement method_missing
Move native_send() to runtime and method_missing dispatcher

In readyness for sending directly to native objects.