add make genpath rules, .path files, updated .top and .year

Add .path files to each winner directory: a file containing
the path to the winner directory from the top directory.

Changed YYYY/.year files to contain the paths, from the top
directory, if the winning directories for the given year.

Changed `/.top` to contain the IOCCC years.

Added `make genpath` rule to the top Makefile and the
year Makefiles to generate the above.

Added FAQ 6.8 to `faq.md` to explain the above.

Updated manifest to reflect recent changes to the list of files.

2005/.year

@@ -1 +1,15 @@
-2005
+2005/aidan
+2005/anon
+2005/boutines
+2005/chia
+2005/giljade
+2005/jetro
+2005/klausler
+2005/mikeash
+2005/mynx
+2005/persano
+2005/sykes
+2005/timwi
+2005/toledo
+2005/vik
+2005/vince