Apply timeouts to methods via meta programming

Usage:

class Foo

def my_possibly_slow_method() sleep(rand 10); end
def my_possibly_slow_query() sleep(rand 10); rand; end

include TimeLimits
time_limit 1.second, :my_possibly_slow_method
time_limit 1.second, :my_possibly_slow_method, :rescue => false

end

a = Foo.new.my_possibly_slow_method # may throw Timeout b = Foo.new.my_possibly_slow_query # may return false