Implement Array[]
Array#concat: Add frozen check
Array#concat: Convert type
Add core/array/concat_spec.rb to spec list
Turn check_frozen into a decorator:

This also lead to having a __topaz_args__ attribute on function objects,
so we can use decorators on Ruby methods
Clean up after check_frozen decorator:

- Don't assume "space" is 1th arg
- Slice varnames based on argcount
- Cleaner import
- Remove a newline
Merge branch 'master' into array-concat

Conflicts:
	topaz/objects/arrayobject.py
Array#concat: Use the coercer
Remove trailing newline
Add "Magnus Holm" to AUTHORS
Merge pull request #315 from judofyr/array-concat

Implement Array#concat per RubySpec