feedparser defines four regexs for end-of-line, but two are redundant.

NLCRE checks for the three common line endings.
NLCRE_crack also captures the line ending.
NLCRE_eol also adds a $ to ensure it is at the end.
NLCRE_bol ... is identical to NLCRE_crack.

It should either use a ^ to insist on line-start, or be explicitly the 
same.  (e.g., NLCRE_bol=NLCRE_crack.)  (It gets away with not listing the ^ 
because the current code only uses NLCRE_bol.match.

(Actually, if the regexes are considered private, then the current code 
could just use the bound methods directly ... setting NLCRE_bol to the
 .match method, NLCRE_eol to the .search method, and NLCRE_crack to the
 .split method.)