Cleaned the root folder for dups

Moved duplicate files to a separate folder and removed unnecesary
files from the root directory

 renamed:    Notes_Interposition.txt -> Notes/Notes_Interposition.txt
 renamed:    GemsOnTuf.c -> duplicates/GemsOnTuf.c
 renamed:    extconf.rb -> duplicates/extconf.rb
 renamed:    tuf.interposition.json -> duplicates/tuf.interposition.json
 renamed:    tuf_interface.c -> duplicates/tuf_interface.c
 renamed:    tuf_interface.h -> duplicates/tuf_interface.h
 renamed:    decorator.rb -> scratchspace/decorator.rb
 deleted:    tuf.log