With -A and -AA, don't send CRs to the standard output.

They don't belong on the ends of lines on UN*X, and the standard I/O
library will give us one at the end of the line on Windows so they're
not needed there.  In the middle of a line, just print a ".".
Clean up the TLV processing loop.

We want to process TLVs until we run out of data, so make the main loop
condition "length > 0".  Break out of the loop if we see an
NFULA_PAYLOAD TLV.

Add in a bunch of length checks, and make those and existing length
checks report "[|nflog]".