Fix 2001/herrmann2 for 64-bit and 32-bit

By chance I looked at this entry again and it immediately popped into my
head how to get it to work. Except for the one in main() the ints need
to be longs. This will now compile and work as expected both with
64-bit and 32-bit compilation.

Disabled make alt and updated .gitignore.

2001/herrmann2/.gitignore

@@ -1,2 +1 @@
 herrmann2
-herrmann2.alt