Make all parsers cloneable about combine HOT 1 CLOSED

They should all implemented Clone though it appears I had forgotten to add it to Choice and AndThen so thanks for opening an issue!

Remember that the parsers requires that all inner parsers also needs to be cloneable (for them to implement Clone themselves) which is not always possible, usually because of satisfy(|c| ...) as closures do not implement clone. If you need to use a parser multiple time in a function you can wrap it in a closure and call it in every position it is needed instead.

let parser = my_long_parser;
(parser, ..., parser)

let parser = || my_long_parser;
(parser(), ..., parser())

(If you'd like I can push a new beta version to cargo though I will otherwise hold of until a larger/a few more changes comes through).

Fixed in 3a0cf4b

from combine.