altered many function to fix issues relating to many(do()), this is mainly around unlist vs paste ideas
added leftover_ to do() so that it can pick it up in the function
added support for returning leftovers in the f function() in do
added expr example and fixed up do loop issues with backwards compatibility
Merge C:\Users\Chapman\Desktop\fparser
Merge branch 'master' of https://github.com/chappers/RParser