[mod] prepare todos for decorator line proxy
[enh] put decorators in a LineProxy (for now)
[enh] test len for decorator line proxy
[mod] rename todo tests
[mod] micro optimisation
[mod] fix todos
[enh] create DecoratorsLineProxyList to make insert work
[enh] test append on DecoratorLineProxyList
[enh] test pop on DecoratorLineProxyList
[enh] test __del__ on DecoratorLineProxyList