functions to extract the output filenames

Use ##&& to mark the output names in the R code and use this function to
summary all the  related files. For example:
[1] "Output:"
[1] " signed_summary.doc" " hahah.txt"
[1] "Input:"
[1] " inputfile.Rdata"

then copy and paste these information to the readme files
write a readme file for each R scipt